1999 CHEVY S-10 FUEL PUMP PROBLEMS

  • Tiny
  • Martini77
  • 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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Tuesday, September 9th, 2008 AT 8:06 PM

16 Replies

  • Tiny
  • Rasmataz
  • MEMBER

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

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Tuesday, September 9th, 2008 AT 8:31 PM
  • Tiny
  • Martini77
  • MEMBER

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.

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Wednesday, September 10th, 2008 AT 4:40 PM
  • Tiny
  • Rasmataz
  • MEMBER

Power the pump direct from the battery and tell me what happened.

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Wednesday, September 10th, 2008 AT 9:50 PM
  • Tiny
  • Martini77
  • MEMBER

I connected another battery to the pump and it starts working, could it be the connector at the pump?

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Thursday, September 11th, 2008 AT 5:50 PM
  • Tiny
  • Rasmataz
  • MEMBER

Could be the connector test it or an open wire on the gray going back to the fuel pump relay.

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Thursday, September 11th, 2008 AT 6:32 PM
  • Tiny
  • Martini77
  • MEMBER

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?

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Monday, September 15th, 2008 AT 4:59 PM
  • Tiny
  • Rasmataz
  • MEMBER

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-

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Monday, September 15th, 2008 AT 5:27 PM
  • Tiny
  • Martini77
  • MEMBER

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

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Tuesday, September 16th, 2008 AT 8:16 PM
  • Tiny
  • Rasmataz
  • MEMBER

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.

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Tuesday, September 16th, 2008 AT 9:28 PM
  • Tiny
  • Martini77
  • MEMBER

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.

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Wednesday, September 17th, 2008 AT 4:24 PM

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