Gas gauge no workie

[Blue71]

On last three Broncos I bought, none of the gas gauges work. I tested the gauges with a 9V battery and they all peg out at Full. I replaced all three sending units(needed to anyway) with brand new pre-tested ones and still nothing. I unhooked the ground back on frame coming out of the pigtail and cleaned it good so I'd have a good solid metal-to-metal connection. Still nothing. Wiring is still factory and is taped all the way from front to back. Anything I am missing? I mean 3 in a row wont work...just my luck.

Thanks,

Andy
Blue71

 

[Broncobowsher]

Does the oil and temp gauges work? (checking for power and working IVR)
Do you have a tank selector switch? (they are known for going bad)
Gas tank sending unit grounded to the body? (sending unit may not be grounded to the tank, frame may not be grounded to the body, etc.)

 

[SinWagon73]

Mine stopped working and it turned out to be the floater, it had a hole in it and filled with gas.

 

[NicksTrix]

what happens when you ground out the lead from gauge or selector? do you see a signal on a test light?

 

[DWB120958]

Replace the regulator on back of gauges (if the Alternator andtemp arent working) but make sure you unhook battery terminals or it will also be toasted...