I replaced the fuel sender unit on my 2000 blazer. Engine will start and run with starting fluid, no fuel pressure at bleeder. It was running fine before the replacement now after pulling the tank a second time I checked for voltage at the pump connector, only get 5v for sender not 12v for pump. Checked pump on the bench , works fine. Checked wiring for bad connections, checked fuel pump relay ok.

 

How's the fuel pump fuse? Turn the key on and check for +12 volts at the fuse as well as at the relay.

 

I'm getting 12v at the relay but I don't hear it pulling the contacts. I cannot locate a labled fuse under the hood or under the dash!

 

There should be 12v at two of the contacts at the relay. One to engergize the relay and make the connection, and another 12v for the fuel pump supply. I don't have the time today to get a wiring diagram for you, but I'm sure that someone else will.

*EDIT* - As a test, you could jumper the heavier +12v wire to the contact to the pump and see if the pump turns on. If it does, then your problem is ahead of the relay.

 

I have replaced the relay with the horn relay, checked that both relays are functioning ok.

 

OK jumpered out the rrelay pump works! Now what??????????? possible PCM?

 

PERFECT example....[sm=rant.gif]
I know I shouldn't expect a response from a post so old.. but this is the exact problem i'm having and[sm=exactly.gif]my point from another post that people should post results and solutions to help other members[sm=icon_beat.gif]..

 

This is a problem we run in to far too often here.

*Moving to 2nd Gen Tech*