Chevy truck fuel pump wiring help.

[Snatch Napkin]

I'm working on a Chevy truck and the owner has misplaced the Chilton's manual I got him. He has a tendency to do these types of things.

The truck is probably a 97 model, 350, automatic, 2wd. His fuel pump has quit working and I just want to make sure it is not an electrical issue before I order a pump. Can anyone tell me which wires do what in regards to to the plug at the fuel pump?


Thanks for any assistance.

[shumpertdavid]

gray wire is always power to the pump on chevy, the ground is black or black/white. There should be 2 ground wires in the harness to the tank, the heavy of the two will be to the pump. Also if you have power, try cranking the motor while someone hits the bottom of the tank with the broad side of a hammer. The jarring will sometimes set the pump to working, it will need replaced.

[Snatch Napkin]

gray wire is always power to the pump on chevy, the ground is black or black/white. There should be 2 ground wires in the harness to the tank, the heavy of the two will be to the pump. Also if you have power, try cranking the motor while someone hits the bottom of the tank with the broad side of a hammer. The jarring will sometimes set the pump to working, it will need replaced.

I appreciate the info, man.

Hitting the tank was the first thing I tried.

[JimD]

I can grab u a diagram off alldata if you need it. If so pm me an email.

[Snatch Napkin]

I can grab u a diagram off alldata if you need it. If so pm me an email.

I certainly appreciate the offer. If I'm not able to get it figured out, then I will let you know.

[Snatch Napkin]

Alright. I just got a free chance to get out there and cycle the key to see what voltage is doing at the fuel pump.

When we cycle the key I see the display change to say 0L then goes back to what it normally says. I cannot see voltage at any point in time.

I am checking voltage by disconnecting the plug. Does the computer require the load from the fuel pump to be present in the line before it will actually send the voltage?

Otherwise I feel like my problem is further up the line. Am I assuming correctly?

[Sleeper]

Check the voltage at the relay under the hood.

Another common problem with these trucks. If i remember right the panel is on the driver side up by the booster.

Concerning the harness as long as your grounded somewhere it should show voltage.

[Snatch Napkin]

Thanks, man. I'll look into that in the morning.

[Sleeper]

If no volt meter is handy just swap it with the other relay in there thats the same. I forget what it controls but the truck would be drivable to the store haha.