2005 blazer @ the fuel pump the gray wire doesn't have 12v power. I'm trying to trace back to the fuse box and it's a pain. I'm having a real hard time with everything being so tight. My question is.....is there any connectors on the firewall for the wires from the fuel pump ? I dont see a connector in the schamatics that I've looked at but a friend of mine says he recalls a connector in the harness before it gets to the fuse box. If there is one it must be behind the distributor or something. Somewhere not visible. I can't see that a wire would be shorted being so well protected but I could be wrong. If there is a connector I could see that it might be possible that water might have got into the plug.Any help or advise is greatly appreciated !!! A very big thanks to anyone with any advice.

 

Here's the wiring diagram. I don't see a connector, either. Have you tried applying 12V to the fuel pump prime terminal? If it runs then, it would rule out the wiring between the relay and the pump.

 

I have the tank out now and I have applied 12v to the prime terminal and I dont have 12v on the gray wire at the pump. So there must be a break in that wire somewhere I just cant find it. I've traced it up to the drivers door but then it looks like it goes to the passengers side over the transmission and then back around over the engine to the fuse block. Everything is so tight it hard to get into the harness and find the wire to probe the wire with a test light. Even if I used a wire tracer I'd have a hard time tracing it. I'm use to working on old school vechicals where you can sit in the engine compartment lol. Cutlasses and stuff. These s10 blazers dont leave any room to work on. Its crazy. I guess I'm just gonna have to give it another try. I thought maybe someone here might have an idea where the wire might rub and get damaged. A known problem of some sort. Thank you very much for your help. Much appreciated 😉

 

You could always do an overlay harness. Which basically means running a new wire and abandoning the old one.

 

Everything is fine with that wire there was no short. I know I could run a new wire but I didnt want to do that. Only if it was a last resort. I'm still not getting power the the fuel pump and the ecm 1 fuse keeps blowing. I was reading a post here from jeff that had the same problem with power to the fuel pump and it ended up being the ignition switch.