The fuel gauge on my 79 D100 doesn't work correctly. It barely moves above the E when I start the truck regardless of how much fuel I have. Never changes, just stays right above the E until I turn the ignition off, and it falls back to rest.

Is there a way to isolate the problem to the gauge, or to the sending unit? I know one of my cars I could just ground out one of the wires going to the gauge, and if it went to Full, that meant the gauge was working. Any shortcuts like that for the Dodge?

 

you can take the 2 wires off the sending unit and touch them together and the gas gauge should rise. i know on my truck the sending unit don't work but the gauges do.