How to test an electric fuel pump - using a test light

2001 GMC 3500 8.1L engine with no fuel pressure. In this video I am showing how to test the fuel pump electrical circuit using a test light and scan tool.

Engine Performance Diagnostics chapter 16

Symptoms
- no start
- no fuel pressure

Fix
- replace faulty fuel pump

Tests shown
- how to measure fuel pressure
- how to test the fuel pump relay
- how to test for proper power and ground to a fuel pump
- how to test the transfer pump
- how to test for a proper ground on your test light
- how to command a fuel pump relay to turn on with a scan tool
- how to test the computers control of the fuel pump relay
- how to determine fuel pump wiring without a diagram

Tools used
- scan tool - Autel MS905 MaxiSys Mini Diagnostic System
- S.U.R. & R FPT22 Deluxe Fuel Injection Pressure Tester Kit

Playlist
- (Chapters 14, 15,16) Fuel Delivery and Fuel Pressure Testing

Related videos
- How to test an electric fuel pump (1997 4.3L Chevy Blazer CPI)
- Low Fuel Pressure from a bad fuel pump ground (Ford Ranger)
- How to test an electric fuel pump (no fuel psi testing) Ford
- No Start No Fuel Pressure Troubleshooting

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!

Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

[danielarney]

Thanks. Thought you where gonna temporarily swap relays. Can't believe last person that wrote was 7 years ago, don't know how many of us screwed out here appreciate you sharing your knowledge, you'll be helping people 50 years from now.

[mike-ypuk]

God is blessing you with a great gift and you are sharing and that is what i call true success. thanks for your hard work may he bless you greatly.

[mikecooper]

Thanks I replaced the fuel pump relay, but because of how you showed the testing at the fuse block, I discovered I simply put the relay in backwards, with the numbers corresponding to the ground and GM using the positive, Works now! Thanks

[aggiespilot]

As a young parts guy I love your videos. From watching I've grown to love the electrical and computer side of automotive repair which a LOT of people shy away from and treat it like witchcraft. I'm saving my pennies for your Ebook so that I can better help my customers with their issues (With the disclaimer that I am in no way a pro technician and could be wrong)
Anyways keep them coming! great stuff Mr. Danner :)

[MrBurt]

This was my 1st video...I did not have to look for another source of info.
Man you ARE awesome. thanks   ....and yes you are blessed with a gift of knowledge and teaching

[iamhomerj]

Nice video. Having trouble with my 2002 2500 Silverado. Now i know how to test before moving on to pump removal. Hoping just a bad ground. Very informative. Thank you.

[scottketchum]

This is what I call a great video, thank you for sharing your knowledge 😁

[orlanmedina]

You're awesome Paul!. Black and white. Even with no knowledge is very easy to do with what you explained in this video

[christesta]

Great video Paul. You make diagnostic testing look easy which it's not. Going to purchase your book. I agree with your viewer you truly are gifted and blessed!!!!

[csgorton]

i'm so used to the old school style of doing things, learning this stuff is just great!! thanks ScannerDanner

[garymarcel]

Man this is a quality video and very universal. Great fundamentals, i will keep this as a reference of my own. Many people young and old will enjoy your lesson

[Justicejamesb]

I just found your channel, awesome man, totally awesome! About time that someone made videos for people that are a little bit more mechanical, have the tools to do stuff. Thank you, thank you, thank you!!!

[jono]

Great video!! It is people like you that help the

[gregscheyd]

very much appreciate the comment about ADAPTERS which allow the relay to remain plugged in, for testing purposes !!!! PRICELESS TO KNOW

[mckoylach]

Paul, you are the best, with these tests diagnostic procedures, without having a high tech tool, it’s great to possess these old methodical skills...thanks...

[PANOS]

Amazing. On every video I am getting my knowledge better and better and even though I am a DIY guy I have started talking to myself and proposing steps before being told on the videos

[nigelstringfellow]

Thank you for yet another really educational video Paul I am learning so much from your site

[MrBurt]

After I got the bed tilted and had access to the wiring....I found you were absoultely right about the color coding.  95 c2500 had different plug...same color code.  thanks so much

[bassment]

Good job man you explained that very well.

[simbas]

Mr. Danner, Loved your video on how to test an electric fuel pump! As a Systems Engineer working on High end computers and such, you make alot of sense in your trouble shooting skills, and the way you explain them. You just saved me a trip to the parts store to buy a Chiltons for my ride! Keep up the good work!