The fuel pump is not working?

ANDY CROFT

MEMBER
1993 GMC TRUCK
5.7L
V8
4WD
MANUAL
157,245 MILES

The truck listed above is a 1993 k1500. No pulse and no fuel pump and I swapped over to carburetor and HEI. And my 4-wheel drive is not working, and my heater is not working either.
Any help with the truck will be appreciated I'm at a loss with it, and I swapped transmission out auto for manual a transmission.

2 Replies

KEN L

MASTER CERTIFIED MECHANIC
47,643 POSTS

We are glad to help but can you start by asking new questions about the heater and 4wd problems? We will handle the fuel pump issue in this thread. There are two fuses and an oil pressure switch that runs the fuel pump I would check the fuses in the diagrams below and if okay bypass the oil pressure switch and see if power is going through it, if so the fuel pump is bad which is common. Here is a guide to help and the fuel wiring diagrams so you can see how the system works, I also included how to change out the fuel pump as well.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

and

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

I included the oil pressure switch location as well. Check out the images (below). Please let us know what happens.

Images (Click to make bigger)