Popping fuel pump fuse after new pump. Help troubleshooting

[91bbc]

I have a 91 c2500 with the 454, 145k miles. I recently put a new fuel pump (delphi) in and it started up great and drove it to gas station to fill it up. The next day I drove it to work and it was running better than ever, but suddenly died while driving, and would not start again. I had it towed home and caught a ride to work.

The next time I tried to start it I did not hear the fuel pump kick on, and checked the fuse on the passenger side firewall next to the relay. It was blown. I tried swapping the relay and tried again, and it blew as soon as the key went into the on position (no turning over). I then unplugged the fuel pump at the pump and tried again. This time the fuse did not blow.

Does this mean my new fuel pump is bad? What is next in trouble shooting? Is there a way to change it out without siphoning out all the fuel?

When I changed the fuel pump I made sure to sand down the frame a little bit to get bare metal for the ground. Also, the fuel gauge seems to still be working despite the fuel pump pop as soon as the key is on.

 

[Erik the Awful]

You likely either have a pinched wire or a failure in the pump wiring in the tank. You're just going to have to start pulling it apart and looking.

 

[91bbc]

You likely either have a pinched wire or a failure in the pump wiring in the tank. You're just going to have to start pulling it apart and looking.

Since the fuse doesn't pop when I unplug the pump the failure must be be between the pump and connector right?

 

[Schurkey]

Since the fuse doesn't pop when I unplug the pump the failure must be be between the pump and connector right?

Yup.

 

[91bbc]

Incase someone in the future with the same problem sees this- I pinched the wires on the right side of the new fuel pump between the bed support and fuel tank. Run the wires on the left side of tank to avoid this issue.