Mechanics

CHEVY FUEL PUMP PROBLEMS

1999 Chevrolet S-10

Electrical problem
1999 Chevy S-10 4 cyl Two Wheel Drive Manual 100k+ miles

I have checked all the fuses in the fuse box and they are working fine, but I am only getting 5volts to the fuel pump at the tank. Is there another relay that I need to check? If so where is it and how do I check it? If that is not the problem what is?
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Martini77
September 9, 2008.




Test the fuel pump relay or swapped it for a known good one its located in underhood fuse block.

Rasmataz
Sep 9, 2008.
Swapping out the relay did not resolve the issue. When I turn the key I get 12V to the pump for a brief period, but the pump does not activate. What can I try next.

Tiny
Martini77
Sep 10, 2008.
Power the pump direct from the battery and tell me what happened.

Rasmataz
Sep 10, 2008.
I connected another battery to the pump and it starts working, could it be the connector at the pump?

Tiny
Martini77
Sep 11, 2008.
Could be the connector test it or an open wire on the gray going back to the fuel pump relay.
AD

Rasmataz
Sep 11, 2008.
Well, I charged the battery replaced the connector at the pump. Using the new splices I checked the voltage at the wires. The combination that powers the fuel pump does not get any voltage to it. All the other combinations of wires get 12v for a second or two when the key is turned on, then all go to zero v except the purple/orange combination which gets 1.27v all the time. What can I try now?

Tiny
Martini77
Sep 15, 2008.
All the other combinations of wires get 12v for a second or two when the key is turned on, this happens bcuz the relay de-energizes

Test the ground wire to the pump-

Rasmataz
Sep 15, 2008.
Sorry to sound stupid, but I don't have a clue when it comes to auto electronics. How do I check the ground wire to the pump?

Thanks

Tiny
Martini77
Sep 16, 2008.
I connected another battery to the pump and it starts working, could it be the connector at the pump?

If it comes On then the ground is good.

Rasmataz
Sep 16, 2008.
With the key on I connected another battery to the connections that power the pump, and it turned on. So that means it is grounded, right? What can I try next? Thanks for the help.

Tiny
Martini77
Sep 17, 2008.

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