I B back. Fuel gauge "again"?

Hot rod, 48 DeSoto, 1st Gen 392 Hemi.
I bought new Stewart Warner fuel gauge and tank fuel sending unit. OHMS same for both. 1st installed, worked perfect. Now reads full all the time? Original 16 gallon tank. Any body have any suggestions.
Jack

Sounds like the sender is stuck in the up position

Agree, but when ignition off, reads E.
I took gauge, hooked Source terminal on gauge directly to fuel tank sending terminal, power wire directly from battery to IGN terminal on gauge, and ran ground directly from Negative on battery to GRD terminal on the gauge. Same results gauge went to full, unhooked IGN terminal, went to E?

When you remove the power it will automatically go to empty. If the float is stuck up then it will always read full. Bang on the tank near the sending unit and see if that makes the float drop. If not then pull the sending unit and see why it is staying up.

Sounds simple enough, even for me. I'll be on it first thing tomorrow. Thanks. Any other thoughts, appreciated.
Jack

Before removing the sending unit unhook the sending unit wire that feeds back to the dash gauge. If the gauge goes to full with that disconnected then the wire is grounded somewhere between the gauge and the sending unit. If the gauge doesn't go to full then the issue is the sending unit itself.

"the wire", meaning the wire from the sending unit? Will check. If that happens, any suggestions where to look for the ground? Could it be possible that if there is no rubber gasked between the sending unit ring and where it fits on the tank?
Jack.

When I unhooked "the wire", still went to full when I turned on the ignition. Give me some places to check for grounding? I'm back to garage to remove sending unit, maybe?

Pulled the sending unit. There is a rubber gasket between sending unit base and tank. I moved the float arm, up, middle and down, gauge stayed on full????.

you now get the fun of tracing the wire from the tank to the dash gauge to find the spot that wire is touching ground.
it may not be fun, but it's the only way to start the repair process.

Like I said you have the sending wire shorted somewhere between the tank and the dash.

unplug the connector behind the drivers kick panel & see if the gauge still pegs when you turn the ign on. this'll tell you whether to move upstream or downstream from that connector to locate the improper grounding

Confirmed. Hook everything up straight, gauges works. As I moved the float, gas gauge needle moved accordingly. Tomorrow I will trace the sending unit wire and replace from end to end. Times like this, a lift would sure come in handy. At 75 years old, crawling under a lowered hot rod, not fun, nor easy. .

I got lucky. Found the break in the sending unit wiring, only a couple feet from the tank. Replaced the wiring, hooked everything back up, gauge working accurately. Thanks to everyone for your help.

Jack

Glad you found it so easily.

Smart move there, too many would have just butt spliced it together. Odds were good another break was fixing to happen.

Thanks to help from MoParts members. The only hitch on the wiring, at the tank unit, wire Red, then as I traced, spliced into Green, the spliced into White for the gauge connection.

glad it was easy to find and repair !
now with that said, did you go a ways further than the repair to see if the wire is getting brittle on the insulation ?

Electric gauge? The sender may not be compatible with the gauge. Fought that with my tank relocation. Talked with a tech at Tanks Inc. and he said I needed a gauge (Autometer) computable with the sender I had. Problem solved.