Fuel pump help!
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7th Gear
Joined: Apr 2024
Posts: 7
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Fuel pump help!
My 2000 c5 has an issue with the fuel pump turning on, it will not run. I’ve tested all electrical components that I know of and the FP and FPR are brand new. I’ve ruled out that it’s not mechanical.
here’s a few test I’ve tried..
Suppling the fuel pump with independent 12V proved my FP works and pushes fuel out.
I then hot wired the relay to stay close and when I put the car to “on” my FP works. This rules out the wiring harness and connector into FP. So far I’ve tried 2 brand new relays and it will not turn on, only with hot wire. I’ve also tried using the horn relay
side note: every fuse in my car is 100%
im lost and I have zero clue what it could be. I’ve ruled out everything I can think of.
here’s a few test I’ve tried..
Suppling the fuel pump with independent 12V proved my FP works and pushes fuel out.
I then hot wired the relay to stay close and when I put the car to “on” my FP works. This rules out the wiring harness and connector into FP. So far I’ve tried 2 brand new relays and it will not turn on, only with hot wire. I’ve also tried using the horn relay
side note: every fuse in my car is 100%
im lost and I have zero clue what it could be. I’ve ruled out everything I can think of.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,508
Likes: 4,000
From: Cape Coral, Florida
The test you performed does NOT rule out the wiring harness or the relay…did you watch the video I had posted on your other post ??…there is a control wire on the relay that energizes for 2 seconds when the key is turned on…have you checked that with a test light ??…did you check the GROUND for the control side of the relay ??..you only got wired the load side of the relay by jumping terminals 87 and 30…the control side must work for the pump to work.
Tech Contributor
Joined: Jan 2007
Posts: 19,398
Likes: 1,139
From: Dyer, IN
My 2000 c5 has an issue with the fuel pump turning on, it will not run. I’ve tested all electrical components that I know of and the FP and FPR are brand new. I’ve ruled out that it’s not mechanical.
here’s a few test I’ve tried..
Suppling the fuel pump with independent 12V proved my FP works and pushes fuel out.
I then hot wired the relay to stay close and when I put the car to “on” my FP works. This rules out the wiring harness and connector into FP. So far I’ve tried 2 brand new relays and it will not turn on, only with hot wire. I’ve also tried using the horn relay
side note: every fuse in my car is 100%
im lost and I have zero clue what it could be. I’ve ruled out everything I can think of.
here’s a few test I’ve tried..
Suppling the fuel pump with independent 12V proved my FP works and pushes fuel out.
I then hot wired the relay to stay close and when I put the car to “on” my FP works. This rules out the wiring harness and connector into FP. So far I’ve tried 2 brand new relays and it will not turn on, only with hot wire. I’ve also tried using the horn relay
side note: every fuse in my car is 100%
im lost and I have zero clue what it could be. I’ve ruled out everything I can think of.
If you are going to keep asking for help, how about actually following some of the advice from people that have been working on this platform for over 20 years?
