Fuel pump ALWAYS getting voltage

[Random250]

A bunch of you guys threw in some good suggestions on my "92 Dead on the Side of the Road" thread. I followed them as best as my limited mechanical and electrical ability would allow, but now we've come down to the wire.

I finally gave in, siphoned and dropped the tank. The fuel pump was dead. I can kinda see why since it's always getting voltage. Key out it gets 7.2 or so. Key on, sharing the load with the other electrical components 1.1. The battery shows 12.4 WTF?? I'd already replaced the fuel pump relay and the eec relay. I think the code reader said error 542 Circuit open, PCM to motor. We had posts of people saying their relays were stuck open, but that doesn't seem to be it this time.

I need a quick fix. They're working on the firehouse and I've gotta get this truck out of the way ASAP. Anyone else got any ideas? I'm thinking of bypassing the fuels electrical altogether. Any suggestions as to where you would hook up if you didn't want to use a dedicated switch, but wanted it to only come on with key turned in ignition?
Ground?

 

[MrShorty]

The fuel pump circuit does always show voltage. I don't understand exactly why, myself, but I've heard that it has to do with the fuel monitor circuit at the PCM's internal circuitry. That's what the 7.2 or so is. The presence of the 7 V doesn't indicate a fault.

Personally, I wouldn't "permanently" wire the fuel pump in differently. If needed, you might temporarily run a hot wire to the pump to get the truck someplace workable.

The fuel pump circuit isn't very complicated. You said that your voltmeter reads 12.4 V at the battery. So, the next thing I would do would be to move to the fuel pump fuse in the power distribution box, and see if it reads 12.4 V there as well. If it's not close to 12.4 V, then the fault is between the battery and the fuse. If it does read 12.4, then move to the relay, and so on down the circuit (ground the fuel pump test lead to close the relay). Where the voltage drops is where the problem is.