Diagnose No Crank No Start Like a ROCKSTAR with Bonus Track!!
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- Опубликовано: 1 окт 2024
- Diagnosing a 2007 Lexus RX330 with a no start from a fairly famous owner- car will not even crank, starter won't even click. Seems it may not be a starter issue but more a control or power issue to the relay.
Also we catch up on some other cases and see how they are doing, plus a major update on the Schrodinger's Box Book by Dr. Ayman Kamar.
To easily learn how to do these diagnostics visit www.schrodingersboxQM.com and get unlimited access to hundreds of training videos for only $3.49/month
Other videos referenced in this epidode:
Thermal camera Review: • Nissan Misfire + Paras...
Locate an AC leak Like A Rockstar: • Locate an AC Leak Like...
Puppies!! • Oh No What did Vicki ...
Matt, I can't thank you, Eric O at South Main Auto, and Ivan at Pine Hollow Auto Diagnostics enough. I have been watching all your channels for quite some time now. Along with Richard at Precision Transmissions. Since watching I have rebuilt 2 transmissions successfully. And I have learned so much about diagnostics. I purchased the Xtool D7 along with many other diagnostic tools that you guys use on a daily basis, hoping that one day I would be able to use them. The Xtool D7 sat on my desk until my neighbour was telling me that see had lost her key fob and had to tow the vehicle 100 miles into the city and a fee of $250 to program the fob. I piped up and said " I think that I can do that for you" she was surprised. Sure enough the D7 had a key relearn feature and what do you know it WORKED!! I has a hero and she was so happy!! She saved a ton of money and gave me $100 bucks. My first earnings for a diagnostic/programming job!! I am so stoked. Give me a check engine light and let me at it! Thanks so much guys!! Fist Pump!! What a feeling!
Fist pump!!! Great story!!
What was the final fix? Starter motor or starter solenoid? And what were you doing with the long screw driver when it finally did turn over with the power probe at 24:20. Jumping the solenoid? Could you jump the solenoid with a screwdriver without the power probe sending power? Or had to do both?
@williambarnett I’m super confused on that also?
Sugarloaf "Don't call us" -- totally remember that tune fondly from the 70's! It's the song that uses the main guitar riff from the Beatles "I feel fine", which I also liked! (And it's a fun diversion to hunt around for other songs that are loosely based on the same riff.)
Awesome man!!! The song is also biographical on the band having such a hard time breaking into the industry and getting a contract. The irony is after Green Eyes Lady, those same producers who rejected them called them back wanting contracts lol! I love revenge stories!!
@@SchrodingersBox Hahaha -- nice additional detail!
Great job, Thanks for sharing! I know from your other videos that you will try to figure things out without a diagram, I feel that on today's cars, it's just not really feasible to remember all the quirks of each car. I always look at a diagram from the beginning. Keep up the great work!
Great observation!!!! yes you are correct. I used to just figure it out but you are right- more and more I am finding that the newer the car, the worse that strategy works lol. also, there are some designs now where if you do the old methods of “let me bypass this” or “let me put voltage to this” it can actually cause major damage because the circuits aren’t what you expect!!!
Great vid as always, for your viewers who don't know why we use relays they are there so you can use a low amp circuit to turn on a high amp circuit, if you look at the wires the control side are thinner then the load side and you can buy relays in different amp ratings.
Great lesson , great story , great 70’s band & songs , great plot twist (the power side switched) , great e-book , great tools , great viewers’ community , great art , great kitten fostering , great ear on the awful compression sound , great automotive charity plans , great prices on everything , great idea for temperature gun use , great screensaver … 👍🏼 I appreciate it all . THANKS MATT !! 👊🏼
hahaha I think you did great at summarizing it all! this was like a variety show episode lol.
Matt, you rock brother as always thanks for sharing.
My pleasure and always great to see you!
I've had 'No crank/ Starts" many times.. because I drive manuals and have pulled started my vehicles more than I would like to admit. :)
I noticed around the 30 minute mark that sign over your shoulder with the X on it , is Elon a viewer? Awesome! Thanks Matt what I enjoy about your videos is you really have to pay attention , i really need to join up, soon as I get my living situation straight I’ll probably do that, inflation is killing us , thanks for the updates on everything!
my pleasure!!
11:50 "Why did the fuse blow?" Because too much electricity was trying to get to the other side?
Green eyed lady lovely lady. Awesome tune and love the 70s rock
All that invaluable information for 5 bucks? The Book! Wow that’s incredible thanks Matt!
Thank Ayman!! he really made is possible.
It seems a bit strange, but wiring the starter relay that way ensures the ECU controls starting the vehicle. This includes the immobilizer (validates correct key is present), remote start capabilities, and the ability to not allow the car to attempt to start if certain conditions are not met. Also remember on a push start vehicle it is necessary as the ECU controls how long the starter is activated, and will shut off the starter if a no start condition happens after cranking for a short period of time. Otherwise the engine would continue to crank continually even if it did not start for another reason (no fuel, bad ignition, etc). Clever, yes?
Oh I totally agree- my question is why doesn’t it do it by controlling the ground side of the control though?
@@SchrodingersBox I am not an automotive engineer, but I suspect that a control wire fault is much more likely to short to ground than coming into contact with another 12v source. Doing so would engage the starter provided that the ignition is on, even with the engine already running.
Would seem to me with a push button start the PCM would not engage starter with an active CKPS signal though. I’d rather have ground fault than a blown PCM for sure!
@@SchrodingersBox correct. I was referring to a fault in the control wiring downstream of the ECU.
Far out! I know that song. Never knew the band name. A new claim to fame.
Best I could manage is a small talk conversation with Chris Cornell's sister backstage with a downstairs neighbor's band.
Matt, you rock brother as always thanks for sharing.
Okay brother.. i see the RUclips plaqué on the wall. And yes!! Green eye lady was that shit bruh!! 70s and 80s music for me...
Good videos 😮 one question.. when you disconnect a sensor and check for power and ground and signal at the conector and it checked out good .. after you connected it back and you back probe with the key on and you don’t have the same reading.. does that mean you have a bad sensor??
No it means the switch for the sensor is open. On an open you will see the votage on both sides of the circuit. If you have amperage through the circuit then of course you will se the voltage drop across the load.
An Rx 330 doesn’t have a prop rod they use hydraulic shocks which tend to fail so maybe he just took em out and has an after market prop rod?
Also they only had the 3.3 liter from 04-06 the 07 was the 3.5 liter or the rx350
I have an o4rx330 and the relays are right in that main fuse box near the brake fluid. Idk why they changed the design but that sucks. In curious if this one was a Canadian model?
You are just awesome Matt 😮 Im so impressed at your wealth of automotive information..
Aww thanks! Glad to pass it along. I still learn every day though- this video was no exception. Always seems I find something new.
I just recently found your channel. I love the scientific method. Also I love your Tran am . I got a 98 trans am ram air, Lots of fun. Great information you have a viewer for life.
Great to hear!!! LS1 forever!! Though mine is a later model corvette transplant for the supercharger project
Those vehicles are over complicated girl couldn't afford the relay and key lock so I bypassed the whole shebang with a door bell button turned it into a push start car over engineered
the lexus fuel pump has its own ecu module and even getting the starter to turn the engine on wont start the car because the rest of the main ecu functions (throttle position sensor, injectors, fuel pump etc) are not being activated, they all work simultaneously, so just the starter cranking isn't gonna make the rest of the components necessary to start the car activate... peace
Okay who’s humming green eyed lady while watching ? 😂
hahahahahaha I have been humming it for 3 days nonstop now hahahahaha
2nd whoo hoo!
holy hell i know sugarloaf and both songs!!!! that is a cool story and payment!! and of course he is mellow!! he was a musician in the 70's! HA!
hahahaha you were already old when those came out hahahahahahahaha
Does crank no start. It turns over but don't run. These short terms helps while I look for issues. Thanks for your post.
Very cool test light 💡
I have been using this for 2 years
I saw it for the first time in SD😎
Yes I love it!! The bright red light and the needle probe for backprobing- it’s perfect!!
Like several other commenters, I don’t know what part was defective. Was it the starter or what?
Great video sir. I wish I had my way to be with you i would've improved so well. You're really a star sir. I love your videos ❤
Wow, i didn't realize you were going to take me way back in time by watching this video.
Classic isn’t it!!!
From the brief googling I did, the Lexus RX 330 shares the 2GR-FE engine with the RAV4 of the same year. I just did that in my girlfriends RAV4 and it really is a proper pain to get to the starter motor. You have to take the whole battery tray out and then the gap is super tight to get the motor in. I got an aftermarket starter on rock auto and it was a smidge longer than the OEM which makes it super tight with the transmission mount. If that thing fails again on me it’s going to be a nightmare to get back out.
Another great video Matt! It’s so great to see the community you have following your channel. You’ve helped us all so much, and I love to see the support for your channel from others.
Thanks so much Nathan!! Yea the community here is EXACTLY what I wanted. It’s so different and more knowledgeable than most any other automotive channel.
I did a rav4 engine changeover years ago and I used a 2 post hoist. I slid a table under the subframe and undid everything, then lifted the hoist and the engine/box/subframe stays there. Much easier to replace the engine this way 😄
I couldn't really see the diagram, but I would bet that the ignition switch actually turns on a larger main relay that the turns on several other things, including the load side at the start relay. I wouldn't think that they would wire the ignition switch directly to the starter solenoid. I bet there's more fuses and relays under the dash. It's still pretty odd though.. I'll have to remember this one. I think this is the first time I've seen something different than the normal constant power there at the starter relay; I would have definitely thought there were issues there until I seen the wiring diagram. interesting.
yes I actually simplified the diagram a bit however the start position does indeed send 12V directly to the load side starter relay. reminded of 1950’s Buick I worked on recently. you are correct in that there are other offshoots from ignition switch to the ECM of course but it is a direct bee-line to that relay! I think it’s “safe” because the relay does the ground side completion afterwards so the switching is inside the relay vs the ignition switch.
Awesome No Crank video!!!! Nice when there is a little twist like that!!!!
If you have a manual transmission car that is a "No crank" and you can push start it or roll start it by popping the clutch in gear, then you can have a "No crank start".
But it is cranking in that case. It’s just cranking without the starter motor
You should look up the proper usage of "begging the question". I know that a lot of youtubers (and others) are using "begs the question" as a replacement for 'raises the question' but that's not at all the proper context for that phrase.
Hint: theres really no reason normal (and intelligent) people like us would ever have a need to use that phrase in normal conversation. Its a logic thing. Like philosophy and what not. I can't really even explain it effectively which is why i suggest looking it up right here on the toob. Ur welcome. ;)
If you happen to be using the word "efficacy" in any capacity, thats pretty much a similar situation. Its very specific and lots of people are using it without looking it up. Context doesnt define anything.
I literally have no idea what you are talking about. The irony that you are trying to help me communicate better hahahahahahaya
I downloaded your free book. Thanks man...
It has a lot of info.. and links.. and the definitions of automotive terms, etc. Just glancing over it: It looks awesome.
Thanks!! The new version is 10X better!! It has probably triple the information.
Hey Matt !!…great video and once again thanks for the shout out !!…just picked up an 08 Corvette with the 6.2 liter LS3 and I’m enjoying it…took a ride up to C&S Corvettes in Sarasota and they said they don’t do a lot of diagnostics so they may be using my “skills”…LOL !!…no, they don’t use a scope either !!
That’s awesome man!! My Trans Am has a transplanted 6.2L LS3 too- supercharged hahahaha.
Yeah I really can’t thank you enough for that Pico. It changed the whole channel. That transducer on the jeep’s radiator to verify the gasket leak…. Just epic man. I use that scope every chance I get!!
First? Wooo... First!
Edit: Great video as usual Matt. My wife has the same vehicle only 2005. I will definitely be purchasing your book, and thanks for all your time and efforts! Glad you survived the pups 😂
yes you are!!
@SchrodingersBox what a turkey!
What was the final fix you did not say that in your video?
I wish you were in South Carolina! I’ve been trying to figure out this 93 Thunderbird crank no start for weeks now 😂
Have you determined it to be a fuel, spark, or timing problem yet?
I'm curious about how big the wires of the igntion switch in this circuit design. Since the starter is ultimately connected to the ignition switch, wont the ignition switch have to have really big wires to be able to handle a huge current? This design is really counter intuitive and defeat one of the purposes of a relay. And that is have a low current on the ignition switch
it uses a relay so the wires are small gauge.
Make sure you remember to change the No Crank, No Start in the book, too!
I'm not arguing with your assessment, nor the outcome, but I missed how you proved that the cause of the starter issue was not ground related. I can envision those seats and steering wheel moving with a so-so ground that might not be adequate to crank the engine. Ground cables and corrosion would have been my starting place to investigate - solely based on prior experience of instrument cluster behavior caused by ground issues in ancient Chrysler products, and other clap-trap automobiles.
Hahaha yes I will do that but probably mention it in the book why it’s just no-crank!
Ground is not an issue on this starter because the block is the ground. No ground cable.
@@SchrodingersBox It took a few minutes for it to sink in, but you proved the ground cable was not the issue when you changed the starter. (Since it worked properly, then.) I was thinking in terms of positively condemning the starter prior to changing it. If you were able to do that 100% before attempting the new starter, please explain to this dummy how... hehe. Have a good night.
Sugarloaf, not Steppenwolf (brain apparently stuck in the 70's)
You just have had a great time in the 70’s lol. Steppenwolf one of my favorites- and my favorite song is indeed magic carpet ride. The 8 minute psychedelic version- not the radio version!!!
Yes ppl know that band.
Sugarloaf green eyed lady !
1.5 volts of voltage drop is too much, that is no good
It is in a stuck starter where source battery voltage also drops due the the high amperage.
OK, I am an electronic technician well versed in troubleshooting industrial electronics, and I really appreciate your book. I have two Sons that are interested in electrical explanations from time to time and I want to explain things like they are in this book, so where do I sent the $5? PayPal preferred... Thanks
Wow, thanks! Right now a free "draft" version of the book is available at www.schrodingersboxQM.com. The full version is still being revised and will be out in a couple months. We will have instructions available when it launches but it will still be all done through that website.
Yup found the book, love it, I will stay tuned.
"No crank, no start" -- well TECHNICALLY, you could have "No crank DOES start" if you roll start it! That would confirm everything works except for the starter system. But yeah, that would be pretty inefficient to laboriously pursue whether it starts or not when you're going to have to address the starter system anyway.
What do we do
Then it would be called no crank roll start. So it is no crank no start if it won't start by turning the key.
How about hybrid systems that don’t have starter. So no crank by default.
Hahahaha. Well then you can’t differentiate between no crank no start and a no crank start!
I guess it’s just a start or no start??
no crank no solenoid click?
So... In the end. You replaced the starter?
Trying to diagnose my daughters boyfriends car. So he can stop driving my car to work cause im gonna lose it if i cant have my car back soon.
Im thinking it might be his starter, but i dont have a multimeter so its a guess only from watching a million videos today
Why not just buy a multimeter for $10 at home depot?
@@SchrodingersBox I need to, just haven't gotten that tool yet. I'm gonna try tapping on the starter and trying the key again before I do anything else. He took his keys with him in my car, for the last two days. So I have limited time to try anything before it gets dark. 🤦♀️
Great video as usual
turn your defrost on. you ok.
Nice to hear from you all new valuable information. Thanks a lot.
Always my pleasure!!! This was a good one. Learned something new, but then again I do every time.
This guy talks to much and not about the problem
You do indeed. Just stfu and watch the video.
Your too cool, Dude
Different strokes for different folks, I also believe a no crank means nothing happens but to many people, no crank means no start but the starter activates, we see this fact all over the internet so NO CRANK NO START is very acceptable, for a crank no start I also add on why, such as NO START NO SPARK in my library listing. The list of why can get long based on what is missing not allowing a start.
Don't be a hater Bro, you get paid to do difficult-to-access starters, if you don't like a job, turn it away. Thanks for all the videos.
Wow what a story!😮😊
0 seguranta 20 amperi arsa sau scoasa, luata de electriker
Can you make an update video on the covid vaxx injuries and all the young athletes that some people are relating to the jabs? Just wanna hear your prespective like on your original vaxx videos you made that helped me. Right now if you question if it could be the jab there's immediate criticism but I don't know why you can't even question something anymore. Thanks.
Hi Matt. Please help. My car does crank and every sensor is good according to the scanner, but yet there's no spark. What could be the problem.... it's a corsaD z14 XEP engen
Great video. As for Steppenwolf, don't forget Magic Carpet Ride (US Billboard #3) !!
Thank you Sir
Can u help me I have a 2015 Kia Optima my car was recently broken into now I’m Experiencing a start no crack every things come on but want start
sounds like the security reader for the key has been damaged.
@@SchrodingersBox how do I fix that if u don’t mind me asking
You will have to replace it and have a new one programmed. A locksmith can do it.
Seems like the relay is set up like that to eliminate accidental double cranking the engine? ECM won't send power to the relay control if it sees the engine running. Still seems a bit of an odd setup for a car but I typically work on older heavy trucks and construction equipment.
the lexus engines are very compartmentalized meaning almost everything has a sensor or ecu to monitor or control its functionality..
Bro did you have to remove the axle?
Nope not at all. R+R only took like half an hour actually.
Thanks for the shout out !
thanks for the amazing tip!!! It worked absolutely splendid!!!
Enjoy your weekend with all your family around you, Schrodingers Box
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QUICK-WITTED Schrodingers Box
From Nick Ayivor from London England UK 🇬🇧 ⏰️ 07:25am Good Morning 🙏 🌄
Thanks my friend!!
Another great video can’t wait to get your book 👊🏻$5 I’ll pay in advance
Hahaha give us until end of summer and we’ll have it ready! Lots of new material too.
👍
Ack, what were you going to say about the dashboard??? The lights that remain on are my concern. I'm have a no crank & headache. Please elaborate if possible.
Not sure what you are referring to but if you have a no crank then start by checking for voltage to the starter. That’s always easiest first basic step.
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Hi! I have a 2003 gmc savanna van 4.8L. 8 coil packs 4 on one side 4 on the other. One side of the 4 coil packs are getting fire. The other side of the 4 coil packs No Fire! It spinning over but don’t catch! Please tell me what to do to get that fire on the one side of all the 4 coil packs?
Yeah you have one of two issues. Either you don’t have power to that side or you don’t have ground to that side. Check ANY coil for missing power or missing ground and that will confirm it since all share the same power and ground on that side.
Hey man. Caustic Guy here. LOL What a cool story. We get some people once in awhile where I work but I'm not really a name dropper (Mike Pinder Moody Blues) lol but I'm glad you did. I had forgotten about Sugarloaf. It was a different world back then.
Hahahaha Myron personally knows Mike Pinder- they played together often and he has some stories lol
I dont know how to present this, but, saw a newer mazda and the 2 middle spark plugs had 2 wires out of harness that i think were ground. Im guessing a waste spark type of thing? Or im thinking just actual block grounds.
Sounds like a waste spark. The other plugs probably had coils directly on them I am guessing.
Mine shows a P2354 ignition switch
Yes that codes means the fuel pump modules is seeing less than battery voltage. Simply check the voltage at the module as first step and if the voltage is indeed low check for a short on the feed. If it’s not low check then the module may be bad. Usually that’s not the case though.
@@SchrodingersBox low oil pressure light stop engine comes on when accelerating. When it cools off it goes away. My buddy said it was the oil pressure switch, so I replaced it. Wasn’t it. Now he’s convinced it’s a bad oil pump. I noticed they were 2,500 overdue for oil change when it quit running. I decided to pull the VVT solenoids. The first 2 came apart inside. I’ve tried a magnetic pin, but it’s not strong enough. I’m thinking they are gummed up and stuck. Any suggestions for getting them out? Would make a great video…Thanks
Analog digital voltmeter man.... hahaha 😅
Dvommvmm
How much is your paid channel?
It’s only $3.49 per month. Www.schrodingersboxQM.com
Maybe it’s the starter not a compression issue 🤔 Bad armature?
It is!!!!! That’s exactly why I found as the new starter didn’t have that issue. Whew!!!!
Take a couple drum lessons!
I have a French car, and to test mine you have to crank, to test the relay, and some other European cars are same.
Oh good to know!
👍great video
Glad you enjoyed it!!
The prop rods in the trunk
Can I email you? I had hard starts and very random stalling issues/rough idle. I thought it was fuel related so I replaced the fuel pumps and now I have no start. Check compression and its low but the car ran right before replacing the fuel pumps, except when going wide open throttle it was bogging which is what led to the new fuel pump. I am so confused could it possibly be a failing crank/cam sensor causing this issue?
Could be. Could be a million things. What was your fuel pressure showing that indicated the fuel pump was bad? what is your cam sensor signal voltage showing?
@@SchrodingersBox I am not sure the FPR is in the engine bay but experiencing loss of power at WOT. I was told by my tuner I had a fueling issue. Seems like its time for the parts cannon 😅
No click = bad relay or bad ignition switch or wire to relay... My guess at 3:30 minute mark.
la nisan primera este in cabina tabloul de sigurante si relee, stinga jos in fata soferului...in mijlocul sigurantelor
16:14 the 2%!!
Watch this video. You said " that begs the question "
What was your thought on the data interpretation from the diagnostic. What would you have done differently?
@@SchrodingersBox 14:45 is where you said it. Your diagnostics skills are far superior to mine. I have no input on your technical skills. Looks like you're on point to me.
@@SchrodingersBox I'm just poking around for ideas. I'm dealing with a 2013. Yeah, sportage, it was idling a little rough and seemed like it ran out of gas in the driveway. I put five gallons in it and now it won't start. It's basically a crank, no start. But I did get it to fire a little bit with some starting fluid. Oh also, a door was left cracked which killed the battery while sitting for 2 days. Charging the battery currently (pardon the pun) any suggestions?
What data do you have?
@@SchrodingersBox actually, I just confirmed it was a fuel pump. It's on order.
I currently have a crank no start on my 2015 bmw n55 535i .i have Checked everything on my fasttec list at least twice and the car won’t start. The car was working completely fine the day before (no codes engi
Ok so how did you verify fuel, how did you verify spark, how did you verify timing and how did you verify compression. You missed one of those. if the car doesn’t start then one or more of those is missing. there is no other explanation.
(For spark )i used multi meter and receiving 12v to the ignition harness and i used a test light while cranking and i am getting spark
( For fuel ) i don’t have a release valve so i open the fuel line and (car fuel pump prime by opening door dont have to open ignition)after open the door gas sprays out at an high rate so my fuel pump is good
Remove spark plugs and injectors are spraying
(For air and compression ) removed the car intake and it’s s clear .for compression im to sure how to check
Used My obd2 to scan car and got no codes . Found a way to used the ignition dashboard to scan the car and 1 code came P13e5 -ignition and injectors relay control circuit
I’m not sure what to do next. Can’t find the relay
Ok I see no evidence of testing timing, no evidence of compression and no evidence of fuel. For all we know your fuel pressure is 15PSI.
You will have to revisit everything except spark. You have to show timing is correct, compression is correct and fuel pressure is at minimum spec. One of those things isn’t correct. We know that for a fact.
Awesome bro
Another great video thanks for sharing
Anytime Howard!!
Dude, that's so freakin cool!!
hahahaha yeah I did this just to make people jealous hahahahaha!!! nah honestly I really think it’s an awesome story and I’m really fortunate to know Myron.
Can you make videos on compression test
I have at least 12 videos on compressions testing with various methods.
How do you test a Relay if its working or not ?
I simply measure continuity on the load side while activating the control side. If there isn’t load side continuity during control side energization, the relay is bad - even if it “clicks”
I have a 2002 Safari that won't start after lower radiator hose came loose any suggestions?
Could have overheated. Check compression first v
@@SchrodingersBox yes it did over heat..I was driving and it overheated and lost power
Yeah the most likely explanation is at best you blew the intake gasket and at worst the head gasket. You absolutely need to do compression test. Best wishes - I hope it’s not the cylinder head.
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Hi Matt, Is it easier to fry the ECM with a POWER-SIDE switched system, than it is with a GROUND-SIDE switched, or is it equally the same?
Same. The difference with ground side is that it’s much safer for PCM if there is a wiring fault. If PCM provides power and that wire grounds out, you fry the PCM. But if PCM provides ground and the wire grounds out, you don’t blow the PCM but of course that device would always run.
@@SchrodingersBox I would assume that the PCM will have current limiting by whatever means ... fuse. resistor (cheapest option), polyfuse or as part of the voltage regulator for the circuit ... that would be just common sense.
It often doesn’t!!! That’s the thing!!! A fuse in the circuit won’t help on a positive side PCM control because the transistor in the PCM would blow long before a fuse did. You want that fuse to be directly from battery source and PCM controls ground after the load so in event of a short on that power, PCM will be saved if it’s not switching at the time.
Take a fuel injector for example- it has a fuse. And it’s ground side controlled by PCM. If you ground that power out in front of the injector- then no matter what you won’t hurt the PCM. You will just blow the fuse. If your ground wire on the injector grounds out, again, you won’t hurt the PCM (but injector would always be open). HOWEVER- if the injector itself shorts or you short across it with a paper clip, you will blow the PCM, the fuse won’t even blow because the PCM will fry long before the fuse would.
@@SchrodingersBox I am not an expert on ECU design - and if there is no protection circuity and only a fuse - you are right, it will likely kill the transistor. Though I cant imagine that modern ICU do not have protection against it - for example combining a current limiting resistor and a a fuse (or PTC). Or implementing a current limiter that switches off the transistor in case of overcurrent - it wouldn't really take much to implement something like it. Modern phones, computers, chargers are full of power electronics creating numerous voltage rails - almost always current limited. Could be an interesting test on a car that's headed for the scrap heap.
e.g.: US patent US20140347774A1 descibes a sophisticated approach - but much simpler approaches would use a similar setup (just without the staging and the need for an ADC - just simple comparators).
@@SchrodingersBox So is that same thing as installing a fuse between the PCM and any device; the driver would still blow and not the fuse. even if the fuse was 5amps or smaller?
Good job
Thanks as always!!
Great video my friend
We are getting very close my friend!!! I want to make one more major edit while Viktor is out on vacation anyway and then I’ll send it to you for final edit and then you and Viktor will work out the details for the purchase proceeds and then we will launch. I really think at end of summer.
Ok Matt
Book will be very useful for viewers
Great job and clear explanation 👏
did i miss something i thought the purpose of the relay was to carry the load. unless i missed or misunderstood appears the switch is carrying the load it just goes thru the relay the relay just breaks the circuit seems like a waste of a relay.