Fuel pump/electrical issue

1997 CHEVROLET SUBURBAN

107,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC

JBOUZA09

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Just changed a fuel pump. Tried to replace the whole assembly but was not available. Car drove 700 odd miles and has started acting like it did before i changed the pump, randomly quitting, no fuel pump sound in the tank. Relay is new as well. When I turn the key relay clicks. Removed the wire harness fuel pump connector and checked for voltage. There was 8.5 volts. Battery has12.8 at the terminals and the fusebox. What am I missing ???

Jan 6, 2020 at 4:45 PM

SCGRANTURISMO

CERTIFIED EXPERT
4,897 POSTS

Hello,

This sounds like you have unwanted resistance somewhere between the fuse and the fuel pump itself. In the diagrams down below I have included the powertrain management wiring diagrams with the fuel pump wires high lighted for you and a couple of guides explaining how to find unwanted resistance in an automotive electrical circuit using the voltage drop method. This is the preferred method for finding unwanted resistance as opposed to a continuity test. Please go through these guides and get back to us with what you find out.

Thanks,
Alex
2CarPros

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Jan 6, 2020 at 9:46 PM