Fuel Pump will not engage.

1997 GMC Sierra 305 8 cylinder:

Fuel Pump is not getting power. Does anyone know what would be causing this....everything else works except for the fuel pump?

1997 GMC Sierra 305 8 cylinder:

Fuel Pump is not getting power. Does anyone know what would be causing this....everything else works except for the fuel pump?
ECM B fuse
fuel pump relay

Fuel Pump has been replaced. Fuel pump relay has been replaced and ECM B fuse tests good.

Fuel Pump has been replaced. Fuel pump relay has been replaced and ECM B fuse tests good.
You say the fuel pump is not getting power..I'm assuming you have checked to the pump and you have no 12v..if the relay and fuse are good, you have an open circuit between the relay and the fuel pump...

1997 GMC Sierra 305 8 cylinder:

Fuel Pump is not getting power. Does anyone know what would be causing this....everything else works except for the fuel pump?

Hi,
The connector outside the fuel tank is known to corrode or burn and fail to electrically connect.
The wires on the fuel pump inside the tank also have had problems and some new pumps come with a new pump pigtail wire, or a note to replace the pigtail.
There is a little wire with a connector thet hangs out of the harness just behind the fuse box on the fender in front of the brake master cylinder. It is where you can jumper 12 volts and cause the pump to go. it bypasses everything and goes directly to the pump. If the pump doesn't run with the wire jumped to 12 volts, then there is a bad wiring from there to the pump, or a bad pump.
Good luck,
Bob B

Tested the wiring this morning and it showed the pump getting 12V. So we went and got yet another new fuel pump....got it home hooked it all up and it worked for maybe 5 seconds....and then it was dead again.

Anymore suggestion

Update:

Took the fuel pump out of tank and tried it...and it works. Put the pump back in tank and it won't. Anyone have any suggestions as to what to look at that would be causing this?

Tested the wiring this morning and it showed the pump getting 12V. So we went and got yet another new fuel pump....got it home hooked it all up and it worked for maybe 5 seconds....and then it was dead again.

Anymore suggestion
When you checked for 12v how did you do it, DMM, test lamp?
Did you perform a voltdrop test?
did you check grounds?

Check the connector at the sender (where the FP and Sender harness connects to the underside of the sender assembly)..is the connector burnt?
Are the terminals tight?

If you pull the pump again use an ohm meter and ohm the wires from the pump to the connector.

If you pull the pump again use an ohm meter and ohm the wires from the pump to the connector.
An OHM test is an invalid test for wiring concerns. All it does is tells you there is continuity on the circuit.
A VOLT DROP test will tell you if there is resistance on the wires that could lead to a failure.

It's all about basic electrical theory and OHMS law :p

I was just trying to help him with basic tools a home mechanic would have available.
With my ohm meter I can check resistance which causes voltage drop.

We got it fixed. We pulled the fuel pump once again and tested it outside the tank and it ran. Put it back in the tank and it wouldn't. Bent the connecting prongs...and guess they weren't getting good enough contact b/c that seemed to get it to work.

Thanks for everyone's help....it was greatly appreciated.

We got it fixed. We pulled the fuel pump once again and tested it outside the tank and it ran. Put it back in the tank and it wouldn't. Bent the connecting prongs...and guess they weren't getting good enough contact b/c that seemed to get it to work.

Thanks for everyone's help....it was greatly appreciated.

If you had to bend the prongs, this means the female terminals are deformed.
I would suggest replacing the connector.