M38 Fuel Gauge Issue

[Bez]

I've been restoring my M38, and have come up against a problem getting the fuel gauge to work. I have a mechanic doing some of the work, and he has installed a new wiring harness, new fuel sender unit, and now a NOS fuel gauge, but it still won't work. He said it seemed to work for few minutes, then spiked past full and stayed there. Now it just reads E. We suspect a grounding issue, but he says it's properly grounded.. Any thoughts?

Thanks Much
David

[wesk]

If the gauge and sender are the original military type and the correct part numbers for the jeep then I too would suspect a ground issue.

Take a jumper cable or long test lead and clip it to the bare metal of the tank sender and the bare metal of the gauge cluster. Does it work now?

If not check that the gauge case is grounded well to the instrument cluster plate and the instrument cluster plate is well grounded to the dash. Does it work now?

Finally be sure to download the tech bulletin that covers military gauge troubleshooting.

http://www.willysmjeeps.com/v2/modules. ... tit&lid=46

[Bez]

Thanks Wes! As usual your advise is solid and much appreciated! I will go ahead and try why you said. I'll report back after.

d