Fuel pump relay

[RedRider85]

Anyone know were the Fuel pump relay on an 85 blazer is located?

[BUTCHERBOY]

Driver side above the brake booster I think. I wish I knew for sure, but all the stock harness is long gone.

There is sticky thread with diagrams here. Autozone.com too

[mytmouz]

Driver's side fender on mine. BUt I swapped in a complete harness in mine when I returned it to street duty, and it may not be in the original location. I didn't cut any wires to put them there though...

[RedRider85]

Ok so here's the deal. I went to the gym, truck ran fine. Went in worked out and left. Went to start the truck and it fired, idled rough and died and no fuel from then on. It doesn't prime, it doesn't get pressure at the rail or nothing. Do you think it's the pump or the relay? Checked the fuse and it's good. On another note I don't know what pump is in the tank, just know it was swapped out for another one a few years newer that had the right pressure for the TPI. Thoughts? I'm gonna start buy checking the easy stuff first, relay, wiring, etc. IF nothing else works i'm gonna pull the tank and test the pump isolated from the rest of the system.

[BUTCHERBOY]

Old trick for you to try. This isnt a joke either.

Turn the key to ON. Then Take a rubber mallet and strike the side of the tank. It sometimes get a STUCK pump to break loose and work. Saved me from wasting hours chasing parts, soon as it hit the pump took off.

2cents for the evening!

[RedRider85]

Ok so here's an update. I jumped the relay, nothing. checked the wire running down the floor board, not power. ran a wire straight from the battery to the pump and nothing. doesn't even arch when the wires touch. NOTHING. I can't get the pump to run or power to the wire. WTF can it be? I'm thinking a bad ground somewere but that still doesn't explain why i'm not getting power.

[RedRider85]

Ok I figured it out. I dropped the tank and found the pump wires were completely burnt up. No insulation at all. All the wiring from the pump to the relay was burnt up and the relay was fried. It burnt the wire all the way to the to the oil pressure switch. After replacing the pump, sending unit, wiring, relay and such it runs again. I don't know what happened with the other pump, but i'm glad it didn't burn my truck to the ground this time. And for alittle over 100 bucks and a couple days work i have a completely new fuel system and pump electrical system. Plus the injectors are quieter and the motor runs smoother and stronger. I bet the old pump was running low on pressure this whole time.