97 5.7L 2500 fuel pump

[zotso]

the fuel pump started working part time i would start it it would run then go somewhere then go to start it agian would'nt start put new fuel pump in and new relay now i don't have no power at the pump wiring connecter there is 12v power at the fuse but at the relay there is only 0.03v what should i check next ?

[SpitAndDirt]

Which pin of the relay are you checking? Second, when you turn the ignition key to On but don't start it, do you hear the fuel pump kick on for about 3 sec and then shut off? You should have four places to test for voltage under the fuel pump relay. With the key on, engine off: You should have two terminals with 12V. Of the other two, one will end up being the wire that leads to the fuel pump and the other is the wire that the computer uses to tell the relay to turn on or off. If you have a little schematic on the side of the relay, I think that terminals 86 and 87(or 87a) are connected when the relay is engergized. You may just take a jumper wire to those positions where the relay sits and listen for the fuel pump. You may swap out identical relays and see if the truck starts. Last, if everything is working corectly, you may need to look at your fuel pressure regulator. I would see if you can borrow or buy a fuel pressure tester and watch the gauge for large fluctuations. -Chris