Fuel pump electrical circuit diagnosis (no fuel pressure testing) GM

[@rudylitwin2268]

One of the best follow along trouble shooting videos I've seen. Thank you.

[@woffordsoverlandjourneys8618]

I have a 95 Chevy Astro van and it had the exact same identical problem with a brand new fuel pump, watching your video and following the instructions and listening very carefully led me to my problem with my 95 Chevy Astro van and the wiring up front!! You are a true detective of auto mechanics and electronics!!!!!

[@ScannerDanner]

Awesome! Glad it helped you

[@liralira7372]

Ddeds

[@mjkru7701]

I am SO grateful, that you shared this video!! Was absolutely losing my mind, with this same problem!! Definitely made my wife happy, cause I don't come back from the shop angry as heck anymore! LOL Thanks again for your expertise! 👍🍻

[@vdub8679]

The very methodical trouble shooting alone was worth watching.. Shows the value of a good schematic and info from the customer.

[@ScannerDanner]

Thanks so much!

[@wyattoneable]

I appreciate that you consider us DIY guys who can't justify a scanner. I do realize sometimes you just need one. Great diagnostics. That was actually fun to watch.

[@ScannerDanner]

+wyattoneable thanks man

[@reweydewy]

This guy has taught me so much on the electrical side of automotive repair

[@ScannerDanner]

+reweydewy thanks man! It shows a symbol next to your name that says "supported", what does that mean? I've never seen that before?

[@Jordan-xi2fs]

Spent around £800 on parts including fuel pump , ams sensor , vaccum pump , few relays , over 50 hours of watching youtube videos and around 2 weeks of not having transport to get the same problem sorted , turns out the ecm fuse was blown.
Thank you so very much for this video I was a day or two away from scrapping my car

[@jimbuford4147]

Great vid as usual. I really like how you explain the wiring diagram. It makes it much more clearer.

[@maryprpic3994]

What color is the fuel pump power supply on a 89 buick century

[@rwbishop]

I've had to do similar things on older POS vehicles... I suspect you did this, but when comes to cobbling stuff of this sort, I like to at least slather up exposed terminals/connections with silicone dielectric grease. Great videos, Thanks!

[@despiertatetuqueduermes6918]

Great video, thanks...our Astro van has the same problem, we thought it was the fuel pump, it was not, we changed the ignition module, the relay was melted, and we didn't know about the module behind the battery...we will try tomorrow....we have two weeks with the van trying and my husband found your video, very interesting and useful, hope we can fix the car....regards from Mexico.

[@christopherolson7833]

Awesome video. You went thru all the steps on checking the fuel pump in a process of elimination that most can follow and do for themselves. Thanks for the method of teaching you used for this application. I would not change what you are doing. So much good information that was given in this video. Thanks

[@ScannerDanner]

Thank you!

[@SantanaOutdoors813]

Great Video. I had the same issue with my chevy express van and was puzzled also after running through the same tests at first. Finally figured it out because of this video. Thanks.

[@MCking3243]

Thank You for the video. Same problem here with 98 pontiac grand prix. Never would have checked the ecm fuse if it wasnt for your video,
Good work!!

[@jasanrichards]

Driving down the road yesterday in my 1994 safari. Turned on the headlights and my car stopped running and wouldn't start. Battery fine, would turn over like it wanted to start but just wouldn't start up. Found this video and immediately checked the 4 pin connection behind my battery. Was a real pain trying to unplug it but when I finally did it had the exact same issue same pin melted. This video was a huge time saver. Thank you it's really appreciated!

[@ScannerDanner]

Awesome! Super glad this helped you

[@keithfrisell4271]

Scanner Danner Iam a ase and gm cert mechanic and have been service manager of a gm shop I think the diagnostic steps u have taken were right on par with this repair. This was my first video of urs that I have watched just to see how knowledgeable u r . U clearly have skills and I look foward to watching more videos and possibly learning from u Thx and good job . Keith

[@ScannerDanner]

Thanks Keith!

[@colinrawlings9532]

keith frisell hngbgybygv

[@Unknown-qp7mv]

Hey thanks for the video bro. I've watched countless vids on my issue and u have so far a good way of explaining step by step.

[@simonhall4895]

Excellent tutorial. This UK Chevy owner is now your No1 fan! Thankyou so much.

[@ScannerDanner]

Glad to help! Thank you

[@RudiKiefer]

Fantastic job ! Very methodical, excellent camera work. I've got the same initial problem (no start, no fuel) on my 1991 Astro, and will go through these procedures now. Thank you very much for explaining everything so well. Much appreciated !

[@user-uj1xg7hb2u]

Danner, i don't know how can i thank you for the great knowledge, Skills and Experience you are sharing you

[@ScannerDanner]

Just by watching like you are!

[@mlb0611]

BTDT, on those Astro vans, did the exact same repair, truly a better repair than replacing that block,common failure on those vans

[@ScannerDanner]

+Michael Berg thanks Michael!

[@chancefigueroa1020]

Exact same problem I'm going through with my 2004 Chevy Colorado right now, so glad someone has the answer!

[@NobodyAskedForThis]

Great video. I do prefer using a power probe, personally for a couple of reasons. Mainly because a test light might show that there is no voltage by not lighting up at all but if it does light up it tells you that there is voltage but doesn't tell you how much. Also, I like the power probe because I can send full battery voltage to a load ground to check ground integrity. If the circuit breaker trips in the power probe, the circuit can handle current. The power probe 3 has a display which shows voltage which is great. A test light has it's place and is useful but the power probe offers much more information to me when diagnosing. I feel it makes me more accurate and faster which is always my goal.

[@billygilbert7911]

This video saved my but today. I turned the headlights on while driving and boom it died. I thought fuel pump for sure. Now I know how to troubleshoot that.
The only thing I didn't like is your comment about not checking the fuse first. That's task one with all electrical.
I resolved my problem by removing the wire from the factory plug (cut it off) and attached to the positive on the battery.
Runs like a champ now.

[@allensandven0]

At 58 I feel like I’m back in school every time I watch his videos , this particular one I used the same process to trouble shoot a 92 Isuzu 2.6 l Itec that was giving similar symptoms. And when I say back in school I’m referring SD institute . I’m not a tec or mechanic never had any training , in fact a carpenter by trade but as I get older I’m trying to get another skill set that isn’t quite so hard on the body . Thanks for great training videos

[@ScannerDanner]

Thanks for the comment Allen!

[@leelemon3373]

Great Video. I have a 92 Astro w/same issues. Very complete walk through. easy to follow. Thanks!

[@kennethcollins2354]

your channel is always so good. You have stuff from the do-it-yourself-er to the 30 year veteran great job keep it up

[@ScannerDanner]

+Kenneth Collins thanks Kenneth

[@amunderdog]

Well - I am surprised - When you did not get power at relay it took you a long time to check fuse - Seems the fuse was the place to start - But you got there and managed a fix - I still learned much - Thanks

[@gradytatum7415]

Very good diagnostics to find the problems. Thank you for sharing this video. Grady Tatum.

[@revolutionzerox]

been a while since I've commented on a video. Thank you for all your work and videos. Its nice to learn and watch as you go into diagnostics on a vehicle. watching this on my 70in tv is pretty entertaining.

[@ScannerDanner]

+revolutionzerox awesome, thanks man

[@salvadord.magana1319]

this was a good demonstrationon checking a fuel pump it showed me a lot great job continue the great job Thanks Guy

[@waynebolton4427]

Thanks brother you taught me some tricks on this project on my s-10 v 6 vortec. Never had one those motors

[@luisalejandrolunavillamiza2318]

Great fix... The best tool to be honest was the Wiring diagram... Without that getting direction will be a little more complicated... You're legend...

[@mikewazowski6588]

Merry Christmas Paul Danner
I learn a lot from watching your video
So far I find your video is the best on RUclips
Love to see more 👍

[@rjschroeder5793]

Very good information for my giving situation very helpful !

[@justinrowles9316]

your the man I'm having the same problem with my 95 GMC sierra I will follow what your did to see if that's my problem as well thanks

[@SimplyDiagnostics]

A great lesson in testing methods 👍

[@andrewwmacfadyen6958]

Why do idiots give thumbs down....................
Thanks Paul for a good video using the low tech basic tools approach.

[@ScannerDanner]

+Andrew W MacFadyen don't know Andrew but thank you!

[@laurenhardman3598]

Right. Great video, gotta be one of the better ones. PS is this ona military transport van if not, awesome paint work haha

[@Zentrepreneurial]

Wow, this was awesome. I have a 1995 chevy astro van. I am looking at my vehicle when I see this. Same issues for me. I have replaced my electric fuel pump twice. My previous mechanic stopped charging me when I had this issue of cranking but not starting. He would fix it. He also installed a battery switch because my battery kept draining. The wires are so old. Anyway, my new mechanic, the old mechanic's friend, is maybe new to this. He thinks it is the fuel pump. Maybe it is but maybe it is this thing behind the battery. I see it there and I see the other things on the left side. This video really shows me what is happening. Sorry to say I have no background in electrical stuff or I would attempt to fix this thing myself. That area behind the battery sure looks worn. I was planning on selling this back to the county who wants to get these old vehicles off the road. I know this van will run for 300k. It now has 155k. The exhaust it puts out sucks. It is rickety on the freeway and the AC leaks. And the windows don't work. Other than that, it is great. Thanks again for this video. Cool to see how things work in there.
Another question I have is: Is there any way to decrease the exhaust on this vehicle? It does put out a lot of pollution.

[@ScannerDanner]

As long as you're catalytic converter is still good and your fuel trims are normal. That's about all you can do (for exhaust clean-up) but that should also be fine.

[@YourAverageFNAF_Edits]

just one more week to get your book thank you for the videos

[@ScannerDanner]

+Luis Alonso thanks so much Luis!

[@4793bigdaddy]

Excellent vid. Very good diagnosis.

[@Pablo_Automotive]

Another fantastic video.
Paul, merry Christmas and a great greeting from Spain.

[@vettper]

very informative and gives me hope I can find out why my Vette isn't priming the fuel pump.

[@Builtaroundnature]

What was your solution?

[@kramnull8962]

Thanks alot for this video. My 92 S10 2.5L had a ground issue from me replacing the Blown OEM speakers with the same size 9x4 and 6x4 4-WAY replacement speakers. According to my friend, he said that the Chevy electrical system keeps a circuit through the speakers even when the key is out of the ignition. My battery would be exhausted within an hour or so of being shut off. Anyways when I got back to the truck and disconnected the speakers, the fuel pump wasn't supplying fuel to the TBI, no matter what. I had seen the pt 261 or 12101870 connector at the back of the motor dangling without a cause. Sure enough following your lead, hooking that up to the to the positive, I struck smelly gold. I know there is a burnt front driver side speaker connector, where it must have shorted. That's the only thing I have spotted as of yet. I hope to find a fuse blown. I am not sure, I left the radio out, and unhooked the speakers. That might be the fuel pump problem for me. I'm going to have to dig deeper. You're video is the only thing on the net that described the PT 261 connector, and what it does. Thanks again.

[@gabinotrujillo8405]

Wooaaoo great diag sir , tanks for compartment to us.

[@courtneysmith4354]

awesome diagnose . thanks scannerdanner for a wonderful year av trouble shooting .

[@ScannerDanner]

+Courtney Smith thanks Courtney!

[@telmosouza]

Paul, maybe you already know this trick, but I would like to share with others. Instead of using the test light, I wet my fingers with water and with one hand I touch the T pin ( violet wire) and with the other hand I am pulsing the battery positive.

[@eldoradony]

I owned a 93 Astro from new until last March. I had the same issue. There are some other common issues that they have that take a bit of time to find but are amazingly simple fixes. That part is not available, I clipped mine from the junkyard.

[@bronco4life]

Another great video!! Thank you Master!

[@user-uj1xg7hb2u]

I'm Great Auto Electrical Troubleshooter here in Malawi because of your videos big up Paul

[@ScannerDanner]

Love this, thank you!

[@sereous67]

Great video. This was my exact issue. And from the looks of the connector, it happened before to previous owner. So I couldn't find a plug like that yet so I temporarily fixed it. Or you can just replace the power block with one from a truck which what I might do if I can't find a good connector plug. Video was a great help. 👍👍

[@mattw1393]

Merry Christmas to you and your family Paul. Loved all your videos this year.

[@ScannerDanner]

+Matt W Merry Christmas to you to Matt!

[@johnbravo7542]

You are one clever man,learn't alot from you

[@rpsspain1966]

Great diag and repair, all vehicles should have that feed for the fuel pump lol. hope you have had a good Christmas.

[@ronnez781]

good job. fun to watch n learn something new. thanks..

[@billyr9840]

Nice, low tech and all ! As usual nice diagnostic approach and fix ! Paul, Merry Christmas to you and your family !

[@ScannerDanner]

+Billy R Merry Christmas Billy!

[@tkme88]

Awesome! I appreciate you guys!
My car is 95 Astro which is exactly same model of this video, and it had a same issue which I could figure out it watching this.
Thank you!

[@ScannerDanner]

Let me know what you find

[@darrencarey8024]

Keep it goin mr. D . always grateful

[@whitetiger8652]

Enjoyed the video Paul.

[@rockon76]

absolutely wonderful video bro I have watched I have no clue how many videos you are the very best I believe this has also fix the problem on my GMC van I won't know until I test it I have been trying to figure it out for months almost identical to what this vehicle's issues were I can't wait to test would have never thought of looking behind the battery you are a great help and comfort my friend God bless you

[@buttabean7949]

I just fixed my 94 Chevy Astro Van had the exact SAME ISSUE....You made my day thanks for the video!!!

[@wysetech2000]

Excellent diag and repair, Paul. You and your Family have a happy holiday.

[@ScannerDanner]

+wysetech2000 thanks bro.

[@abjr2010]

this was great , better than mystery theater. CSI SCANNERDAN

[@BradhallhavasuAz]

thank you you are the best you helped me so much

[@patw52pb1]

Thank you and all those involved in the efforts and production of this channel.
Merry Christmas, Happy Holidays and Happy New Year to all.
May the new year bring you, your families and friends much health, wealth, happiness and peace.

[@ScannerDanner]

+patw52pb1 thanks man! I wish it was "those involved", it's just me.

[@andreagili4589]

+ScannerDanner Happy holidays and merry christmas to you and your beautiful family Paul !!! :) A hug

[@andreagili4589]

+patw52pb1 Happy holidays and merry christmas to you too man :)

[@ozzstars_cars]

This was diagnostics at its Best! Great job Paul and Happy New Year

[@ScannerDanner]

+Ozzstar thanks brother!

[@79wobbie]

that one was good I never expected that but over the years I have learned expect the unexpected I'm going to have to try to remember that one

[@georgebonney90]

Great video,thank u mr danner

[@steveklein2722]

the wiring schematic is 4.3L. The engine is 5.7L. I don't have resources to compare the two, but you had a difference you spoke of regarding the number of pins. Time mark was 19:xx
I have the same issue, researching my cause.

[@ScannerDanner]

eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1=
This is a diy version of the same service info and diagrams I use. Hope it helps

[@wtbm123]

Looks like a good fix to me , Better than new

[@Inkd_watkins]

Great Video Paul

[@chancebrown9597]

bro u saved my ass I now know this proccess in diagnosing in an egucated form of open closed current my blaser 92 4x4 had this happen I knew the pump was good but I knew my icm and ditributer were in working order becouse I could start by selfpriming pour gas in the tbi but only ran that gas out but no curent behind I checked fuse only visioly my mistake also were I lost my way u r the master jedi u saved me from pure darkside of scrapping distruction of that pos 4.3 becouseonly other thing I could think it was valvs body thank you u do good work

[@rhkips]

That looked like a fairly common GM four-pin connector; I think it should be the same connector they used for the ABS harness in the mid-90s. It's rather large, if I recall? I've seen 'em floating around on the racks at parts stores, though you may have to Dremel it to get the keying to fit. :)

[@sethmorton8539]

Thank you for this info

[@89makeba]

My 08 impala ss having the same issue. I'm stuck but I'll will follow your directions.

[@fognnorway6471]

having the same issues with my 92 astro. beating my head against the wall! changing one part after another. uncle.

[@variablethrust]

merry Christmas to you and family Paul. hope it's a belter for you all.

[@ScannerDanner]

+variablethrust Merry Christmas to you too!

[@Phantomas2011]

BEAUTIFUL PAUL!!!
Now I need to apply your wisdom to my lovely heap 🥰🥶
Leor

[@williegillie5712]

Nice work scanner danner

[@Bergred]

even though half of what you said went in one ear and out of the other (my problem), I learned alot ..thank you

[@ScannerDanner]

lol, just keep watching me my friend. You will pick up the terminology and methods. Thanks!

[@mechanicandskills7215]

fantastic job

[@jasonmiller9027]

great video...! helps out a lot! i have a 00 chevy silverado doing the same thing just can't find the bad connection on the truck...

[@ScannerDanner]

+Jason Miller look for areas in the harness near heat and areas that can move

[@jasonmiller9027]

+ScannerDanner thank you...how can i find the diagram that connect my headlights to fuel pump like in your video that would find my problem...? thnk u again u have me in the right direction

[@123Knam]

Great video!

[@elihu217qd5150]

you rock, that's awesome, thank you.

[@automotiveelectronicsfroms2699]

It always amazes me how other channels they think they know the vehicle but they spend that much time on it and then all of a sudden they have to come back to the wiring diagram if you would start with the wiring diagram and see the components that are there you would say 50% of troubleshooting time right there

[@ScannerDanner]

Did I start with the diagram? 😅

[@cincomorales]

BRAVO ! Great job now that why i subscribed to your chanel!

[@phillipmurray5516]

Good job learned a lot

[@theomusch276]

aul
was a good case
I heard you say that you could not hear the injectors because they are under the intake manifold
We use a stethoscope
I work at the AA in Holland so often been the fast road where much noise is
hope to have made a small contribution

[@jesromerg]

Wow... mate, thanks for sharing your knowledge with the community it's incredible the experience that you have.... Well done.... I would like to ask you if would mind you to guide me in a good direction to troubleshoot a fuel priming problem? I have a Toyota Prado 1998 using the 3.4 lts 5VZFE Engine... which is the same used in Tacoma or 4Runner in US from that era 1990-2000, when I turn the key on, the fuel pump does not prime at all but when I cranking the engine suddenly the fuel pump turn ON and the COR relay click and car running ok... Sometimes take me 2 attempt to start the engine, the first) to move the crankshaft and receive the signal from ECM and activated the pump that way and the second) to actually cranking with fuel on the line!.... I have learnt from your videos that the computer has few input in order to communicate with the COR relay, but guessing mine has Alzheimer cause forgot about sending that output signal... which sensor you know are involve in the priming process? I rule out few things EFI is working due I am able to use the car, fuel pump is working too, checked relays and fuse..... Actually I did a test forcing the fuel pump to operate (like the priming action) through the toyota diagnosis port +b and fp with a paper clip, and the fuel pump worked fine then cranked the starter and the car started in the very first attempt!!!! Have you hear something like that? priming action missing.... Well mate excuse my broken english, but you got the main idea hahaha, thanks in advance I do really appreciated any advise!!!!

[@timthemechanix]

I was just looking for the fuel pump test lead location to see if I could use the fuel pump to drain fuel from a tank that has held this fuel from back since this video and got caught up watching the whole video. This 94 S10 pickup has a mint body, interior, new tires but threw a rod on #1 cyl. Could not find one of these early vortecs so I took the bottom end from a '99, used the '94 top end and TBI intake. Had to modify the oil pan on the '99 so the slave could bolt on. The '94 came with a metal timing chain cover that took 2 extra mounting bolts then the newer block so I welded them closed. Runs but 4+ year old gas and has to go so I know what I'm burning.
Anyway, great diagnostic class vid here. Thanks.
Oh, I have a Modis Edge with the 19.4 update. The code it brought up was a 228. OBD 1 has 2 digit codes. Called Snap On, they couldn't say why and said to run it under a Sonoma. Finally got the 2 digit code running as a Jimmy.

[@ScannerDanner]

Not sure where the fuel pump test connector is on you S10. I think it is under a relay box on one of the inner fenders? I think this video may help as I believe I was jumping it
ruclips.net/video/09_wQ9yQ85A/видео.html&lc=UgyybGui5AtK7FbxhW14AaABAg
If not, a good wiring diagram will help you
eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1=

[@rbarr1200]

That was awesome!

[@PIANOSTYLE100]

Dan here is an update still trying to fix my expy. Expy failed going up hill on short out of town trip. replaced fuel filter that was clogged.. ran perfect for 3 days. It failed after errands in a parking lot.. went to get it.. i drove it home.. for 2 days cranked perfect.. continued to run gas out over the next few days so the fuel pump would be easier to change. It failed to start again for five days. Researched . I have Chilton's ECT. There is a limited amount of info in them. I am an ex electronic tech. Understand relays ECT. So watched videos ECT. Checked Schrader valve had gas there. I decided to turn the engine over.. it started (we are dealing with an intermittent here) I took it to a neighbor and he put a bid tool on it.. not a cheap one.. it initially said misfire on cylinder 4.. that made sense because when it quit, it did misfire going up hills I told him to clear the memory.. He found no codes..no cam sensor problems, no crankshaft sensor problems, always has had the sound of prime, never checked voltage at fuel pump relay or pump itself. I hesitate to pup 12 volts to fuel pump willy nilly, as it may feed back and destroy electronic infrastructure. I know this can be the inertia switch (they sometimes are intermittent). It could be an insulation leak to the chassis. I don't know if I am getting spark.. it seems like like the obd tester would catch that.. The problem is that it is intermittent. I notice this doesn't have the normal spark plug wire setup and I think this is cop setup. I am a little confused how to properly check for spark do I use a noid. Oh yes it is only showing about 30 psi on idle and 35 on acceleration maybe a little higher at high rpms. Also my fuse board under the hood and below the steering wheel does allow pull and replace of relays. If it comes down to it I can fix boards, but if it's a expensive chip.. that probably won't be happening.. I suspect we are dealing with an obvious component. If any body can give me a detailed description of how this all works please do so.

[@ficotobar361]

I love your job ,no more neflix for me

[@vehdynam]

Wow ! very interesting. Thank you.

[@anthonynicholls8010]

Scanner danner you really good 👍

[@edwinsandoval1130]

merry Xmas sir my respect to you as instructor I can't wait to see more videos god bless be safe for the holidays.thanks all the info see you 2016 I'm taking diesel classes I just finished my auto.

[@ScannerDanner]

+edwin sandoval where are you taking your diesel classes my friend?

[@edwinsandoval1130]

Los Angeles trade tech college sir

[@ScannerDanner]

+edwin sandoval okay cool. I thought maybe you were coming to my school (Rosedale Tech )

[@timpedraza2085]

Awesome Job Thanks

[@Amcautomotive602]

Seen that a lot very common issue
Went to look for a new connector at a junk and mostly found burned ones as well

[@bradybell6129]

That's where a forum that specializes in that model is valuable. I use probetalk.com for my Probe.

[@bryans8193]

Hey Paul, first off I thank you for all the great videos! I have a 93 suburban throwing me a trouble code 54. Could you steer me in the right direction for testing for this code. Do I have a bad ground or wire somewhere?

[@FORDTECH313]

Happy New Year scanner danner God Bless

[@steviepii]

Very well done. I have a fuel pump issue, believe it's electrical. I just wish I had better wiring diagrams.

[@ScannerDanner]

Where to get service info (some free, some paid)
www.scannerdanner.com/forum/post-your-repair-questions-here/3757-need-service-info-check-here.html
I highly recommend the DIY Mitchell one. For $20 you can buy a 30 day pass for individual cars and have access to the same diagrams I use.