As a last resort to fix my never ending fuel pump problems, I decided to run a wire straight from the fuel pump relay to the pump power harness directly, as I'm assuming there is just a phantom ground/short in the line somewhere that randomly decides it doesn't feel like powering the pump. So I did a test run with 10 gage wire (although the original looks more like 16-18 gage) and gave it a shot. The fuel pump is definitely getting power, but now the car won't turn over. This is with a brand new pump and starter. I think to myself that the only thing that I've changed is the wire, so I hook everything back up the way it was, and the car starts up with no problem. Does wire gage matter for fuel pump power? Or is there some critical component between the relay and the fuel pump that isn't getting power when I ran the line directly? I certainly may be looking at the wrong drawings online (or not understanding them), but it looks like it is a straight shot from the relay to the pump. Any suggestions/advice would be appreciated. Thank you.
1999 2.2 Sunfire Fuel Pump/Wiring Question
- Thread starter JasamHen
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You are working with the engine compartment fuse box, the relay to the far left?
If I'm looking at the correct diagram the relay has 4 terminals, 85 and 86 energize the relay from the PCM. 87A provides power for the pump by sending it out via 30.
Are you running a wire from 87 to the fuel pump?
If I'm looking at the correct diagram the relay has 4 terminals, 85 and 86 energize the relay from the PCM. 87A provides power for the pump by sending it out via 30.
Are you running a wire from 87 to the fuel pump?
I was just looking at the wiring diagram on the AutoZone website (attached here). I don't see any numbers, just that a grey wire runs from the relay to the fuel pump. I pulled up the compartment fuse box and tapped in to the gray wire running from the only gray wire I saw running out of the right area. Do you have something more detailed?
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I googled 1999 Cavalier fuel pump relay diagram. Have you tested the other terminals with a voltmeter or test light for power and ground?
Did you remove the relay when you tested the pump?
You definitely have the correct relay?
Did you remove the relay when you tested the pump?
You definitely have the correct relay?