1996 chevrolet C3500 dually with a 7.4 L put new fuel pump in tank and got new relay,but now no power to pump ,and I checked the fuses,was told it might be the oil pressure switch but I cann't find that oil pressure

SOURCE: Problem with Chevrolet 4.3 Vortec fuel pressure / oil pressure relay

a bad fuel pump relay will not cause vehicle to only run under 50. the oil pressure switch does bypass relay when pressure builds up. if you are having problems with running need to check fuel pressure. possibly caused by clogged fuel filter

SOURCE: 1991 camaro RS Fuel pump not working- no power to pump

If the oil pressure switch has two wires on it it may be one that shuts down the pump. I'm not positive but I think it completes a ground circuit, not the hot side though (but may run through a relay.) There should be a pump relay under the hood with a group of other relays. I don't have a wiring diagram for your car but you can get a basic diagram in most inexpensive manuals. They wont usually give you locations but at least you can get an idea of how the system works. There usually is a fuse. If the fuse block is not labeled, use a test light and probe the back of every fuse for power with the key on (takes about ten minutes and faster than trying to find info) change any that are blown. The most likely culprit is a relay, so after testing fuses look for it. (usually on drivers fender or on right side near firewall.) Worst case, trace the power lead all the way through the harness 'till you find where power begins.Testing is important here...I could give you much better info if I was there to do it for you. Most important is to stay "on track" till you find the place where power ends. Don't jump all over the place or you will end up doing an incomplete test.

SOURCE: 1996 chevy tahoe fuel system

i am having the same problem with my 96 pickup i am getting low voltage to my fuel pump i have traced the wires back to the front the purpel wire is the one with low voltage i replaced fuel pump also fuel relay and still have low voltage

SOURCE: 1987 chevy S10 engine idle problem

relace the throtle air idle valve.The temp switch will allso cause this problem.

Mike Butler

• 6674 Answers
• Posted on Jul 26, 2009

SOURCE: no power on fuse of fuel pump chevrolet wt 1500 4.3 liter

Can you follow orange wire back to ECM, & there may be a fusible link in that wire.