I've got a K1500 truck and it quit pumping fuel.

I've replaced the fuel pump and pump relay and no luck.

After digging in deeper it appears that I'm not getting power to the pump side of the relay circuit. I think this might come from ECM? I have a Chilton's manual, but it doesn't show much.

I'm going to see if I can borrow a scanner tomorrow morning to check the ECM.

Any other advice???

 

Yes, don't bother with a scanner. You can just as easy jump the top two pins of the ALDL and count how many times the check engine light flashes. It will flash a 12 three times, then flash trouble codes.

The electrical circuit for the fuel pump goes through an oil pressure switch. Usually located under the distributor. And there is a fusable link in the main wire near the main fuse box under the hood by the relay.

 

OK, I'm now an expert.

The relay heats up the red wire which bypasses the oil sensor. The red wire is the Prime. It's what you hear first running the pump when you turn on the key. Once it's running the relay changes state and it has to have oil pressure or it shuts the pump off. THe hot fuel module is just what they call the entire in-tank assemebly. "It has hot 12vdc and is in the tank" What happened to me was, as I was re-installing the tank with new pump etc, I didn't notice that when I attached the ground wire (blindly on top of the frame) the wire broke off the ring terminal...no ground, no circuit. I got it all back together today and it runs fine.