The Auxillary fan switch we used is from a 1980's BMW. It was sourced from our local parts shop but can be purchased online. tridon.com.au/products/Tridon/35/483/switches-and-sensors/2014/thermo-fan-switches/278/TFS106
VAG car of similar era had them too, my Audi Coupe had same. Probably same supplier, Bosch, Siemens or VDO. As said, you want to right operating range.
BMW Part numbers are: 61318376440 for an 80c/88c part (94~99 318ti) 61311364272 for the 91c part 61311364273 for the 99c part 61311378073 for a 91c/99c part If opting for a dual temp switch, the connector can be had from most E30's, E36, E38, E39 and E46. Pretty sure the connector changed for the e6x e7x, e8x and e9x cars.
Question: What is the reason for wiring both fans to the same relay? Or, is one maybe bigger than the other? Wouldn't one always run with the ignition on? Just trying to dot my I's before I consider tackling this project.
Timely for me, I've been thinking of putting my electric fan back in, the past few days. Will be wanting to pick a good temperature switch for purpose, if so.
@@murph9935 no. That was the spacepast. You've since converted to metric, the spacefuture. I can't believe the rest of the USA is deliberately delaying the spacefuture as long as possible.
@@murph9935 The only place muricans use SI units is space exploration (specificly ISS because they are obligated to do so), so your argument kind of makes no sense.
We use both, and the minority of us that payed attention in school learned both as kids. Its not exactly hard to switch to what ever measurement system makes the most sense for the task you are doing. If you meet an American that doesn't know how to use something like metric or celsius or any of that, it means they are an idiot.
over 324,000,000 americans, and a good majority of them wouldn't know SI units if they fell over them. yes they're trying hard to catch up, but it'll be generations before they're up to speed with the rest of the world. then it's a matter of the smaller 'imperialist' countries (Liberia and Myanmar/Burma) and there's no guarantee there
If you want to remember the relay pin numbers and never forget them. Relays are BET-A (pronounced better) In the order from lowest to highest 30 - Battery ( High amp input) 80 - Earth 85 - Trigger ( What trips the relay to provide power to active) 87 - Active ( High amp output from relay)
I have learned more about understanding wiring watching Skid Factory than I did with 5 years as a mechanic and 18 years in the parts industry. Sure you learn basics/theory, but you cover the details. Keep up the awesome work.
Chainsaws are a distraction, but I do like the little background bird calls that slip into the Skid Factory videos now and then. It reminds me that this is not being filmed on some sterile sound studio. It's in a working shop out in the countryside. Nature. Gotta love it. (when it isn't leaping up in front of your dirt bike and breaking your bones)
Another good thermo controller would be the davis craig one. They are around $50, have independent control over 2 fans, an input for the ac compressor, shows the temp and also allows you to adjust what temp the fans kick in. Pretty sure the range is some where around 40- 120 degrees c
Just came back from slapping a 1uz in an mx63 cressida to realise i can't use the stock fan (among other things). So that little thermo switch trick is what i call a perfect timing! Thanks guys!
A basic on/off switch for your fan is kind of low-tech old school. Look up PWM fan controllers if you want variable speed fan control for quiet operation under normal conditions. Using the diode to make sure the fan is running when the A/C turns on is still a good idea if your PWM controller doesn't have an override. Keep sharing these little electronics how-tos, so much of modern tuning is in the electronics and it's great info!
Before I start watching this video, just wanted to say that I have my own method for wiring thermo fans. Some thick ass wire to the batttery and fan, and a heavy duty toggle switch. Just switch it on when needed. Speaker wire and a small crappy switch is not a good idea. It starts fires. I know this from nearly burning my car to the ground one time. My solution works alright, but I'll watch this and probably re-do it because Al knows what he's doing a hell of a lot more than I do. Edit: Awesome video. Pretty simple concept, or maybe he just knows how to explain things well. Diagram helped. I'll have proper fans that turn themselves on in the near future.
I know I've said it over and over again but Al, I am so greatful for the knowledge you share whether its stuff I've forgotten along the way, new stuff or just a refresher, it's great to have someone with such an extensive knowledge of vehicles that's willing to share that knowledge with the world. THANK YOU!
I'd prolly listen to Al talk about anything. I kept trying to think of a witty "I would prolly listen to Al talk about..." But everything thing I could think of, I was like Damn...I would listen to that and be interested, I bet other people would too lol...much love brudders.
Timely info for my project, as the way I had it wired up before decided to melt the power wires out to the fans rather than blow the fuse. I know how to properly do it, but have always been, for better or worse, a "don't fix it if it isn't broken" type. Going down the rabbit hole of pwm control when I fix it here soon. Side note, if you showed up to most any car show I've been to with a 1uz in a late 50's Chevy like that, pitchforks would likely come out, grumble grumble, some BS excuse on how carbs and leaky 283's were how things were meant to be, etc. I love it!
I have spent the last few days surfing the youtube high seas for a proper video on how to do this, all i had until this video was people just wiring them upto a switch on the dash, congratulation on beeing one of the only people on youtube who actually know what they are doing. Question, I have an 80s sh*t box with no ac, can I get away with using a 1 pronged sensor or will I have to do extra steps (welding, drilling and tapping not an option at the moment), but the 1 wires seem to be the right size for the stock port. cheers in advanced.
Great video guys. Being the genius I am, when I finished wiring my thermos in I tested them only to discover I had a massive amount of air blowing back out of the front grille 🤦♂️
Al and Woody this was excellent! I learn so much from watching you guys. After watching this, I can wire in the thermo fans for my old man's 302. Thanks a lot!
It's worth noting that the relay in Al's diagram is a SPDT (Single Pole Double Throw). Both terminals the fans are connected to switch at the same time. Many relays you'll find are SPST (Single Pole Single Throw) where the middle terminal is 87a. If you're following Al's diagram make sure you've got a SPDT relay or you'll be really confused about what's happening if you replicate his circuit.
Ford medium duty trucks in the 90s used a diode that was the same package and fit as a atc blade fuse, we use them alot for the same fan control because its heavy duty and fits in a regular fuse block
Oooooohhhhh finally a top tip I can give AL, rather than the other way around... I have used this sensor, but in a much better place. Just behind where he's put it into the modified bleed plug, there's a "bridge" joiner between the two heads. I just drill a 6mm hole in the middle, then run a modified spade bit using the 6mm hole as a center to create a nice big flat land for the sensor to seal against (20mm). I then open the hole further with the drill and run the M14 tap into it. You first drain a bunch of coolant out and pull the top hose off, so you have a vacuum cleaner suck all the swarf out of the top radiator fitting as you drill. Works great and it's not the highest point of the motor where you can have clearance issues with the bonnet in cars (rather than the C10 or suchlike where there's heaps of headroom). Having that sensor sticking up out of the bleed point just looks funny, this is heaps tidier IMO
I always put the thermo switch on the cold side of the radiator. This works really well and even better in cold climate since it isn't always necessary to start the fan if the airflow trough the radiator is high /cold enough.
I have a sc400 and I've been tryin to figure out a good and eazy place to put it. I know this video is old but it helped soo much in where to put the switch
Wonderful advice! Ive been trying to figure out how to do the fan wiring for my car and that is way simpler than what I was coming up with. Please do more videos like these, theyre super helpful.
Good old thermofans. See all to many of them on the ignition on switch method even with ecus capable of controlling them. Hopefully more diy guys watch this and learn from it
Had mine hooked to ignition in a Camira that I drove from Sydney to Lightning Ridge then to Kingaroy area in Qld, back to Sydney and then up to Cairns without failure.
You could also use another relay (yeah more parts) if you don't have a diode. Use the voltage on the A/C to turn on the 2nd relay, which then turns on the fan.
That BMW thermo switch is a real all rounder. If you have a late model KTM500 EXC that boils in the tight stuff and frustratingly the fan never comes on, swap out the KTM part with this switch and you’ll never have the problem again.
May be helpful to point out that there are a couple different layouts with 5-pin relays. If the output terminals are listed as '87' and '87b' this method will work because they are both NO (normally open) contacts that get closed when the coil is energized. If the output terminals are '87' and '87a' this method won't work. Terminal '87' is still a NO contact, but '87a' is a NC (normally closed) contact. This means that '87a' will be connected when the coil is not energized, and it will switch to '87' when the coil is energized. Using the drawing, Fan 2 would constantly run until the temperature switch closed, then shut off and Fan 1 would turn on.
I think the diode is located in the wrong place... Seems it should be immediately following the thermo-switch, before the wire junction. Cathode toward thermo-switch, anode facing the junction.
Great way of doing it! Did similar in the early 2000's when I chucked a RB20 in my 180sx (a dumb thing to do). Had a boss welded into the thermostat housing and I think it was a Peugot switch though. We purposely used a slightly lower range switch to allow for the temperature difference. Worked a treat!
Should be a fuse to the thermoswitch, a fuse to the positive supply before terminal 30, and then a fuse for each fan after switching to each fan too :)
I use a pressure switch on the liquid side for the A/C system (usually just use a high side safety switch on a T same one used to cycle the A/C clutch) and run the switch on the Negative leg (pin 86). By putting the switches on the Negative leg I don't need a Diode. As always great video.
TdrSld you always need diode or resistor parallel to coil no matter where you switch it. Or you dont if spark over the switch is ok and no electronics involved then ok. But diode is there to provide path for coil current as if there is no diode to "continue the loop" after switch is opened coil energy will be dissipated with a spark somewhere. In bad case the point for spark is at relay coil lacquer layer slowly destroying the insulation on coil and breaking that relay. Normally it is just small spark inside the switch which those usuallu handles quite long time, but having the switch on pos or neg side has no difference for this. Just like capacitors do not like shorting out coils dont like opening live circuit, except in ignition where this feature of a coil is used on purpose.
I know this is 3years old but… You should put your fan temp switch near the water pump intake. This will turn the fan on only when required. By placing the switch near the thermostat, once the engine reaches operating temp, your fan will run nonstop… 😉
Still got that Gatebil stubby cooler I see!! Love these videos btw guys, I am a sponge when its comes to educational automotive videos and love learning from you Al :)
Great vid fellas! (Not)Pro tip from me. A lot of the BMW e36 TFS are a 3 pin switch (two different temperature ranges) that you can use to control the 16" 2-speed fan out of a BF-FG Falcon (later model, big single fan with a power resistor and 3 pins). Wiring in two relays you can have the low fan speed setting (~8A running) triggered from the low-speed switch, and a high speed setting (~20A running) from the high speed trigger. You could also have the AC trigger the high-speed side. This will start and run the fan on low speed until it needs to hit high speed. It's even kinder to the fan and your car's electricals as you wont be switching on/off the full load current (in-rush current can be huge for a large fan), but a little more complicated on the wiring (but still relatively simple once you have a diagram).
I've always had trouble with thermal switches like that. Eventually they all go out of range and activate at different temperatures. That's why I only ever recommend adjustable fan controllers that you can adjust as your thermal sensor ages. Also allows for you to tune your activation temperature and sometimes your hysteresis. I get this is a cheaper option but the headaches aren't worth it for me.
@Yoda You should also have a diode from the thermo switch so that the power from the A/C doesn't go back upto the switch - if not done it may reduce the life of the thermo switch.
A good source for automotive diode are GM mini fuse style, easy to find, available new, and since it's a mini fuse style you can easily wire it in with any mini fuse holder.
Only detail missing that would probably help people understand is: "why do you need a relay?" You need a relay because most of the circuitry in the car is low power (ie. low-voltage and low-current) and although this circuitry is good for control (acting like a brain) it is too weak to drive big things like fans. Even if you get your fan or whatever to turn on it may actually cause your wires to melt. So to fix this, you can have full-power connected to the relay and use the control circuitry (low power) to trigger the relay into passing on lots of power to big beefy things like lights and fans. But Al is right - there's lots of good info right on youtube. If a video gets too technical or whatever don't lose heart just look for another video that fits you better.
Awesome video, loving these useful bits of actual information especially as I send this video to a bunch of mates as now I can prove they are wrong haha.
That plug is for getting the air out of the cooling system. Also this video came at the right time. I need to do an electric fan conversion on my SC400 because I am getting ready to put a Procharger on it. Here in the USA the market for the 1UZ is limited at best. Can you all recommend a company that makes larger injectors for the 1UZ?
aren't some of those 5 pin relays normally open or normally closed on the two outputs so in your whiteboard diagram fan one would always be on, and fan 2 come on with temp/air con, and number 1 go out? just in case i've got the dumb.. thought i should ask
There are some relays that keep 87a and 87 on when the relay is energized but yes you are correct that the normal relays you will find most places would function as you said.
If you put the thermoswitch in the return from the radiator the fan will only run when you need it. On the engine, the fan will run even if you're cruising and don't need the fan. Both could be used in parallel as a failsafe. A diode or something to suppress the inductive spike from the fan motor would be good too.
With a single post fan temperature switch you can do the same set up. You just need to have the relay coil between the ignition switch and the fan temperature switch. In the case of A/C you just need to introduce a second relay where the A/C diode will drive the second relay coil and you arrange the relay contacts so they deliver the full current to the fans via a fuse.
Yes, the power to pin 30 (fan supply) needs fusing before the relay as its direct to the battery, the thermal switch supply needs fusing as its after the ignition switch, and every fan after the relay needs fusing with ratings based on individual fan current needs.
I think that was just an error on the whiteboard. Yes, both need a fuse and only fan 2 was shown with one. As toby said below, better practice would be to fuse wire 30 near the battery as well as it is unprotected from shorting out as shown. In practice that's probably because these guys are mounting the relay right next to the battery
Please fuse your supply before the relay, try to put fuses for all your non-factory electronics within 30cm of the battery wherever possible when taking power direct from the battery.
I had an Experience already with a retrofitted circuit, long story short, it shorted and was not fused and it burned the relay and associated wiring, scaring me shitless. I now run a 30 amp inline fuse so I won't burn my precious truck down.
To be thorough, you should be using TWO diodes. One from the compressor supply line & the other from the temp switch, with both cathodes connected to terminal 85 on the relay. As for the diodes themselves, the common 1N400x would be considerably close to it's max current rating when powering a Bosch type relay. Whereas an 1N5404 would have ample headroom for this task.
This is such a great resource. But I wonder if someone can answer this for me. I have an R33 GTST Skyline, I want to convert from the viscous fan to electric fan. There is already a thermo sensor in the radiator. Should I leave it plugged in and splice into it to run to the relay? I assume as pointed out its used for the AC as well (I still have AC)? Also do I need to do anything else to the old viscous /clutch fan assembly other than remove it (anything with wiring)? Bonus: I also have a Link G4x ECU; is there a better way to do this using the Link?
I have a question, can this concept be used on oil coolers ? I thought of using the same fan swithc on an oil line. The plan is to try put this on my bike (oil cooler only, no radiators, and modified the engine a bit to much). And i live in tropical climate. But i was thinking about the working temperature of oil compared to water. They should be around the same ballpark, I suppose.
Tridon TFS110 and TFS111 are 3/8" are good for v8's - TFS111 is best. If you have a/c you use another relay to turn on the fan. Ford 40 amp relays available on EA to AU can handle most fans. If you are using the FG single fan the Davies Craig controller works well as it turns on the slow speed before the fast speed
Nice one, I'm sure my Peugeot fan is wired in series with my switch with no relay. Power > Fuse > Switch > Fan > Ground. So it's even simpler than a relay setup :)
![THE SKID FACTORY - [QUICK TECH] How to make a Throttle Cable](http://i.ytimg.com/vi/75neB7OrctU/mqdefault.jpg)
The Auxillary fan switch we used is from a 1980's BMW. It was sourced from our local parts shop but can be purchased online. tridon.com.au/products/Tridon/35/483/switches-and-sensors/2014/thermo-fan-switches/278/TFS106
VAG car of similar era had them too, my Audi Coupe had same. Probably same supplier, Bosch, Siemens or VDO. As said, you want to right operating range.
G'day Al thinking outside the box I see😉😊👍👍
On ya buddy .😉
BMW Part numbers are:
61318376440 for an 80c/88c part (94~99 318ti)
61311364272 for the 91c part
61311364273 for the 99c part
61311378073 for a 91c/99c part
If opting for a dual temp switch, the connector can be had from most E30's, E36, E38, E39 and E46. Pretty sure the connector changed for the e6x e7x, e8x and e9x cars.
Isn't the 14 x 1.5 the same thread pitch as spark plugs and o2 sensors. The tap should be commonly available at most parts houses.
Question: What is the reason for wiring both fans to the same relay? Or, is one maybe bigger than the other? Wouldn't one always run with the ignition on? Just trying to dot my I's before I consider tackling this project.
This is the sort of info we all need. Not, "hey look, I bought a supercar!"
Barje. Waffles
Solid stuff that anyone wanting to set their car up right can use
Timely for me, I've been thinking of putting my electric fan back in, the past few days. Will be wanting to pick a good temperature switch for purpose, if so.
"Don't know what a relay is? *Find out.* "
😂 Love this guy
Trashing on Muricans for not using SI units allways makes my day better.
SI units didn't get us to the moon. :^)
@@murph9935 no. That was the spacepast. You've since converted to metric, the spacefuture. I can't believe the rest of the USA is deliberately delaying the spacefuture as long as possible.
@@murph9935 The only place muricans use SI units is space exploration (specificly ISS because they are obligated to do so), so your argument kind of makes no sense.
We use both, and the minority of us that payed attention in school learned both as kids. Its not exactly hard to switch to what ever measurement system makes the most sense for the task you are doing. If you meet an American that doesn't know how to use something like metric or celsius or any of that, it means they are an idiot.
over 324,000,000 americans, and a good majority of them wouldn't know SI units if they fell over them.
yes they're trying hard to catch up, but it'll be generations before they're up to speed with the rest of the world. then it's a matter of the smaller 'imperialist' countries (Liberia and Myanmar/Burma) and there's no guarantee there
If you want to remember the relay pin numbers and never forget them. Relays are BET-A (pronounced better)
In the order from lowest to highest
30 - Battery ( High amp input)
80 - Earth
85 - Trigger ( What trips the relay to provide power to active)
87 - Active ( High amp output from relay)
86 is negative.
@@dicktaylor2600 BETNA? Catchy.
30 isn't battery. It's just INPUT. It can be positive or negative.
I've never seen an automotive relay with an '80' terminal.
@@dicktaylor2600 - or positive. You just need a positive and negative on 85/86, either one can be the pos or or the neg.
@@TheTalonts unless you have a Ford Bosch 40 amp relay with an inbuilt diode
A master class from professor Al, what a way to start a Sunday.
Norway Gatebil for your lemon squash!!! Love it!
Definitely using this at TAFE as a teaching resource
Those chainsaws were the most perfect background track to a skid factory vid. Elevator music for the enlightened.
Thanks 👌👌👌
Very informative. The only change I'd make is the fuse in line to pin 30 and as close to the battery or power souce as possiblr.
GATEBIL cover for your lemonsquash😁
Norway and gatebil would love you guys to visit us🙌🏻 it is the best car track weekend ever!!
Agreed. Trip from NL was totally worth it. Will come back for another time!
I have learned more about understanding wiring watching Skid Factory than I did with 5 years as a mechanic and 18 years in the parts industry. Sure you learn basics/theory, but you cover the details. Keep up the awesome work.
Chainsaws are a distraction, but I do like the little background bird calls that slip into the Skid Factory videos now and then. It reminds me that this is not being filmed on some sterile sound studio. It's in a working shop out in the countryside. Nature. Gotta love it. (when it isn't leaping up in front of your dirt bike and breaking your bones)
Skid Factory Videos - Online learning at its greatest
Another good thermo controller would be the davis craig one. They are around $50, have independent control over 2 fans, an input for the ac compressor, shows the temp and also allows you to adjust what temp the fans kick in. Pretty sure the range is some where around 40- 120 degrees c
damn, pretty cool!
Just came back from slapping a 1uz in an mx63 cressida to realise i can't use the stock fan (among other things). So that little thermo switch trick is what i call a perfect timing! Thanks guys!
Thanks mate you'd be surprised how hard it is to find a simple video like this
Excellent topic and video. For those in the USA, STANDARD MOTOR PRODUCTS TS288. Turns on at 91C, which is about 195F.
A basic on/off switch for your fan is kind of low-tech old school. Look up PWM fan controllers if you want variable speed fan control for quiet operation under normal conditions. Using the diode to make sure the fan is running when the A/C turns on is still a good idea if your PWM controller doesn't have an override. Keep sharing these little electronics how-tos, so much of modern tuning is in the electronics and it's great info!
Before I start watching this video, just wanted to say that I have my own method for wiring thermo fans.
Some thick ass wire to the batttery and fan, and a heavy duty toggle switch. Just switch it on when needed.
Speaker wire and a small crappy switch is not a good idea. It starts fires. I know this from nearly burning my car to the ground one time. My solution works alright, but I'll watch this and probably re-do it because Al knows what he's doing a hell of a lot more than I do.
Edit: Awesome video. Pretty simple concept, or maybe he just knows how to explain things well. Diagram helped. I'll have proper fans that turn themselves on in the near future.
I know I've said it over and over again but Al, I am so greatful for the knowledge you share whether its stuff I've forgotten along the way, new stuff or just a refresher, it's great to have someone with such an extensive knowledge of vehicles that's willing to share that knowledge with the world. THANK YOU!
Al is such a wizard when it comes to electrics.
So I now know you don't need to go to the ingintion for a ignition source. 👌
Thoroughly enjoy these "quick Tech" great bit!
I do enjoy your no frills approach to your videos 👍
Al's diagram is perfect for hooking up dual horns too (if you replace the fan switch with your stock horn circuit). Thanks Al!
You mean the horns would blow when the A/C turns on?
@@fascistpedant758 you have me thinking as soon as summer gets here, i'm going to find out...
I'd prolly listen to Al talk about anything. I kept trying to think of a witty "I would prolly listen to Al talk about..." But everything thing I could think of, I was like Damn...I would listen to that and be interested, I bet other people would too lol...much love brudders.
Timely info for my project, as the way I had it wired up before decided to melt the power wires out to the fans rather than blow the fuse. I know how to properly do it, but have always been, for better or worse, a "don't fix it if it isn't broken" type. Going down the rabbit hole of pwm control when I fix it here soon.
Side note, if you showed up to most any car show I've been to with a 1uz in a late 50's Chevy like that, pitchforks would likely come out, grumble grumble, some BS excuse on how carbs and leaky 283's were how things were meant to be, etc. I love it!
I have spent the last few days surfing the youtube high seas for a proper video on how to do this, all i had until this video was people just wiring them upto a switch on the dash, congratulation on beeing one of the only people on youtube who actually know what they are doing. Question, I have an 80s sh*t box with no ac, can I get away with using a 1 pronged sensor or will I have to do extra steps (welding, drilling and tapping not an option at the moment), but the 1 wires seem to be the right size for the stock port. cheers in advanced.
The skid factory library of knowledge. I dont need it today but i might need it tomorrow. thanks
Great video guys. Being the genius I am, when I finished wiring my thermos in I tested them only to discover I had a massive amount of air blowing back out of the front grille 🤦♂️
I have done this too lol
!
It's good if you drive in reverse a lot.
Mate, at least you did the right thing and tested it first!
thanks yoda been doing this manually when ever i stop
Al and Woody this was excellent! I learn so much from watching you guys. After watching this, I can wire in the thermo fans for my old man's 302. Thanks a lot!
What a time we live in indeed. 👍
Simple, straight to the point. Good job lads!
I've done a lot of thermo installs and never thought of using a switch like that! Game changed! My project lexarse is getting this for sure!
little current controls big current.. I think I was just saying something like that last night. Love more skid factory!
It's worth noting that the relay in Al's diagram is a SPDT (Single Pole Double Throw). Both terminals the fans are connected to switch at the same time. Many relays you'll find are SPST (Single Pole Single Throw) where the middle terminal is 87a. If you're following Al's diagram make sure you've got a SPDT relay or you'll be really confused about what's happening if you replicate his circuit.
Ford medium duty trucks in the 90s used a diode that was the same package and fit as a atc blade fuse, we use them alot for the same fan control because its heavy duty and fits in a regular fuse block
Oooooohhhhh finally a top tip I can give AL, rather than the other way around... I have used this sensor, but in a much better place. Just behind where he's put it into the modified bleed plug, there's a "bridge" joiner between the two heads. I just drill a 6mm hole in the middle, then run a modified spade bit using the 6mm hole as a center to create a nice big flat land for the sensor to seal against (20mm). I then open the hole further with the drill and run the M14 tap into it. You first drain a bunch of coolant out and pull the top hose off, so you have a vacuum cleaner suck all the swarf out of the top radiator fitting as you drill. Works great and it's not the highest point of the motor where you can have clearance issues with the bonnet in cars (rather than the C10 or suchlike where there's heaps of headroom). Having that sensor sticking up out of the bleed point just looks funny, this is heaps tidier IMO
In two position relays the center pin is normally closed... Awesome explanation!
I always put the thermo switch on the cold side of the radiator. This works really well and even better in cold climate since it isn't always necessary to start the fan if the airflow trough the radiator is high /cold enough.
I have a sc400 and I've been tryin to figure out a good and eazy place to put it. I know this video is old but it helped soo much in where to put the switch
This video is going to useful,I plan on putting a set of twin thermos from a ef/el falcon into my eb.
Wonderful advice! Ive been trying to figure out how to do the fan wiring for my car and that is way simpler than what I was coming up with. Please do more videos like these, theyre super helpful.
Mate you are an absolute life saver
Good old thermofans. See all to many of them on the ignition on switch method even with ecus capable of controlling them. Hopefully more diy guys watch this and learn from it
Had mine hooked to ignition in a Camira that I drove from Sydney to Lightning Ridge then to Kingaroy area in Qld, back to Sydney and then up to Cairns without failure.
Legend Al! Gotta wire up a fan for my mishimoto half rad for my honda, just what i needed 🙏
You could also use another relay (yeah more parts) if you don't have a diode. Use the voltage on the A/C to turn on the 2nd relay, which then turns on the fan.
That BMW thermo switch is a real all rounder. If you have a late model KTM500 EXC that boils in the tight stuff and frustratingly the fan never comes on, swap out the KTM part with this switch and you’ll never have the problem again.
To non-car people this must be one of the most boring videos available on youtube, but I could watch stuff like this for hours.
May be helpful to point out that there are a couple different layouts with 5-pin relays. If the output terminals are listed as '87' and '87b' this method will work because they are both NO (normally open) contacts that get closed when the coil is energized. If the output terminals are '87' and '87a' this method won't work. Terminal '87' is still a NO contact, but '87a' is a NC (normally closed) contact. This means that '87a' will be connected when the coil is not energized, and it will switch to '87' when the coil is energized. Using the drawing, Fan 2 would constantly run until the temperature switch closed, then shut off and Fan 1 would turn on.
Thanks for that. I had been wondering about the open or closed question, and you have answered it. Cheers.
This...super handy and exactly what I needed. Thanks guys!
I think the diode is located in the wrong place... Seems it should be immediately following the thermo-switch, before the wire junction. Cathode toward thermo-switch, anode facing the junction.
Thank you so much Al! Was needing this info explained how you did! Too little info thats not easy to find in detail about it! Again thankyou
Love this Quick Tech format
Great way of doing it! Did similar in the early 2000's when I chucked a RB20 in my 180sx (a dumb thing to do). Had a boss welded into the thermostat housing and I think it was a Peugot switch though. We purposely used a slightly lower range switch to allow for the temperature difference. Worked a treat!
Great video guys...hope you guys are far away from that storm....
Yes a long way away from both.
Great as always! Thank you!
Love the Gatebil can cooler! I have one myself.
This years main event at Rudskogen, Norway is 12-14 July
Should be a fuse to the thermoswitch, a fuse to the positive supply before terminal 30, and then a fuse for each fan after switching to each fan too :)
I see you got some love from scandinavian mates sending you Gatebil stubbys. Really cool!
85 is relay coil earth, good habit as some relays are diode protected
Exactly what I was thinking, been caught with that before. Lots of head scratching before I noticed the little diode pic on the relay.
I use a pressure switch on the liquid side for the A/C system (usually just use a high side safety switch on a T same one used to cycle the A/C clutch) and run the switch on the Negative leg (pin 86). By putting the switches on the Negative leg I don't need a Diode.
As always great video.
TdrSld you always need diode or resistor parallel to coil no matter where you switch it. Or you dont if spark over the switch is ok and no electronics involved then ok. But diode is there to provide path for coil current as if there is no diode to "continue the loop" after switch is opened coil energy will be dissipated with a spark somewhere. In bad case the point for spark is at relay coil lacquer layer slowly destroying the insulation on coil and breaking that relay. Normally it is just small spark inside the switch which those usuallu handles quite long time, but having the switch on pos or neg side has no difference for this. Just like capacitors do not like shorting out coils dont like opening live circuit, except in ignition where this feature of a coil is used on purpose.
Awesome!!!! More of that please!!!! Thanx Al & Woody
I need to do this to one of my cars! Thanks so much.
I know this is 3years old but…
You should put your fan temp switch near the water pump intake. This will turn the fan on only when required.
By placing the switch near the thermostat, once the engine reaches operating temp, your fan will run nonstop… 😉
Gotta love 1uz content...especially in an old Chevy. I gotta get my 1uz swap done in my Malibu
Still got that Gatebil stubby cooler I see!!
Love these videos btw guys, I am a sponge when its comes to educational automotive videos and love learning from you Al :)
Great vid fellas!
(Not)Pro tip from me. A lot of the BMW e36 TFS are a 3 pin switch (two different temperature ranges) that you can use to control the 16" 2-speed fan out of a BF-FG Falcon (later model, big single fan with a power resistor and 3 pins).
Wiring in two relays you can have the low fan speed setting (~8A running) triggered from the low-speed switch, and a high speed setting (~20A running) from the high speed trigger. You could also have the AC trigger the high-speed side.
This will start and run the fan on low speed until it needs to hit high speed. It's even kinder to the fan and your car's electricals as you wont be switching on/off the full load current (in-rush current can be huge for a large fan), but a little more complicated on the wiring (but still relatively simple once you have a diagram).
I've always had trouble with thermal switches like that. Eventually they all go out of range and activate at different temperatures. That's why I only ever recommend adjustable fan controllers that you can adjust as your thermal sensor ages. Also allows for you to tune your activation temperature and sometimes your hysteresis. I get this is a cheaper option but the headaches aren't worth it for me.
@Yoda You should also have a diode from the thermo switch so that the power from the A/C doesn't go back upto the switch - if not done it may reduce the life of the thermo switch.
Keep up the good work. Love ur channel and the loads of experience based advice.
Good timing I needed a diagram how to wired it up 👍🏿👍🏿thanks Heaps
very good video Al. thanks for sharing mate. wish i'd have had this many, many years ago when i reverse engineered this.
Keep up the great work boys, love the vids 🇭🇲👍
A good source for automotive diode are GM mini fuse style, easy to find, available new, and since it's a mini fuse style you can easily wire it in with any mini fuse holder.
I think those are meant to suppress inductive spikes. I'm not sure they'd be great for this.
Brilliant information, thanks Skid Factory
The cap is the breather port when you fill the coolant. Highest point of engine to vent trapped air.
Only detail missing that would probably help people understand is: "why do you need a relay?"
You need a relay because most of the circuitry in the car is low power (ie. low-voltage and low-current) and although this circuitry is good for control (acting like a brain) it is too weak to drive big things like fans. Even if you get your fan or whatever to turn on it may actually cause your wires to melt.
So to fix this, you can have full-power connected to the relay and use the control circuitry (low power) to trigger the relay into passing on lots of power to big beefy things like lights and fans.
But Al is right - there's lots of good info right on youtube. If a video gets too technical or whatever don't lose heart just look for another video that fits you better.
Awesome video, loving these useful bits of actual information especially as I send this video to a bunch of mates as now I can prove they are wrong haha.
That plug is for getting the air out of the cooling system. Also this video came at the right time. I need to do an electric fan conversion on my SC400 because I am getting ready to put a Procharger on it. Here in the USA the market for the 1UZ is limited at best. Can you all recommend a company that makes larger injectors for the 1UZ?
That Ram flow 👌
aren't some of those 5 pin relays normally open or normally closed on the two outputs so in your whiteboard diagram fan one would always be on, and fan 2 come on with temp/air con, and number 1 go out?
just in case i've got the dumb.. thought i should ask
Yeah the 5 pin relays I'm used to are like that, the centre pin is 87a and it's normally closed, and it opens when you energize 85 & 86.
There are some relays that keep 87a and 87 on when the relay is energized but yes you are correct that the normal relays you will find most places would function as you said.
HaaaaHHH Sunday mass with master Jedi :) the sermon was too short!!!
Stop complaining and pass the plate around.
Awesome vid, quick question if my thermostat opens at 82c when should my Thermo fan come on and when should it turn off?
If you put the thermoswitch in the return from the radiator the fan will only run when you need it. On the engine, the fan will run even if you're cruising and don't need the fan. Both could be used in parallel as a failsafe.
A diode or something to suppress the inductive spike from the fan motor would be good too.
thanks for the advices Al !
I like the Porsche/audi 3 pin switches. Great for 2 speed fans.
With a single post fan temperature switch you can do the same set up. You just need to have the relay coil between the ignition switch and the fan temperature switch. In the case of A/C you just need to introduce a second relay where the A/C diode will drive the second relay coil and you arrange the relay contacts so they deliver the full current to the fans via a fuse.
Yes that is true. There are many ways to wire fans but the dual post allows flexibility.
Would you need a fuse for each additional fan added?
Yes, the power to pin 30 (fan supply) needs fusing before the relay as its direct to the battery, the thermal switch supply needs fusing as its after the ignition switch, and every fan after the relay needs fusing with ratings based on individual fan current needs.
I think that was just an error on the whiteboard. Yes, both need a fuse and only fan 2 was shown with one. As toby said below, better practice would be to fuse wire 30 near the battery as well as it is unprotected from shorting out as shown. In practice that's probably because these guys are mounting the relay right next to the battery
I found that very useful indeed :) keep up the good work guys !!
Please fuse your supply before the relay, try to put fuses for all your non-factory electronics within 30cm of the battery wherever possible when taking power direct from the battery.
never used a fuse for wiring fans or lights with relays in my 35 years and have never experienced a problem
I had an Experience already with a retrofitted circuit, long story short, it shorted and was not fused and it burned the relay and associated wiring, scaring me shitless. I now run a 30 amp inline fuse so I won't burn my precious truck down.
Circuit breaker, self resetting is the safest option
@@supersevenn - that's what's known as "survivor bias". Anyone that HAS seen a burnt wire would call you a blithering idiot.
To be thorough, you should be using TWO diodes. One from the compressor supply line & the other from the temp switch, with both cathodes connected to terminal 85 on the relay. As for the diodes themselves, the common 1N400x would be considerably close to it's max current rating when powering a Bosch type relay. Whereas an 1N5404 would have ample headroom for this task.
This is such a great resource. But I wonder if someone can answer this for me.
I have an R33 GTST Skyline, I want to convert from the viscous fan to electric fan.
There is already a thermo sensor in the radiator. Should I leave it plugged in and splice into it to run to the relay? I assume as pointed out its used for the AC as well (I still have AC)?
Also do I need to do anything else to the old viscous /clutch fan assembly other than remove it (anything with wiring)?
Bonus: I also have a Link G4x ECU; is there a better way to do this using the Link?
Hey Al, if you don't want to deal with the threads, Volvo used one on the old RWDs that just pops into a rubber grommet. 9135545 is the part number
I checked that out but the retaining method scares me a bit.
@@alanbutler2579 - what? What could go wrong with a grommet "retention" in a *pressurized system*? It's not like rubber ages and loses its' grip. ;-)
ive used that switch to repair late model BMW that have pulse width controlled fans. thumbs up
I have a question, can this concept be used on oil coolers ? I thought of using the same fan swithc on an oil line. The plan is to try put this on my bike (oil cooler only, no radiators, and modified the engine a bit to much). And i live in tropical climate.
But i was thinking about the working temperature of oil compared to water. They should be around the same ballpark, I suppose.
Yes. The sensor doesn’t discriminate between fluids.
Nice video. Thanks for sharing this stuff. 👌
Tridon TFS110 and TFS111 are 3/8" are good for v8's - TFS111 is best. If you have a/c you use another relay to turn on the fan. Ford 40 amp relays available on EA to AU can handle most fans. If you are using the FG single fan the Davies Craig controller works well as it turns on the slow speed before the fast speed
Nice one, I'm sure my Peugeot fan is wired in series with my switch with no relay. Power > Fuse > Switch > Fan > Ground. So it's even simpler than a relay setup :)
Yes and that is why these switches fail so often.
@@alanbutler2579 I get that, totally man. They're not designed to take the high current draw.
Thanks for the info ;-)
Again in the perfect moment