1969 chevy stepside fuel gauge

[RedMan16]

im having some serious problems with my fuel gauge. it doesnt read correctly anymore. ive used two different gauges and it does the same thing. it doesnt read on the lines for the tank at all its in a whole different area. i disconnected both wires from the gauge which are the ignition and fuel sending unit. if i reset the needle back to empty and dissconnect the sending unit the needle goes right back to the same place. i dont know what the problem is but some help would be nice

[rspears]

Sounds to me like your sending unit is putting out a bogus voltage? It's a variable resistor (slide wire) that varies voltage over the fuel level range. Looks like yours is toast. LMC Truck likely has a new one, if you cannot source it locally.

[RedMan16]

thats what i was thinking it was but even when the unit is unplugged it does the same thing

[Dave Severson]

check your grounds. Is the dash a printed circuit or plug in wires?

[RedMan16]

the cluster is a plastic circuit with the wires running through it to each gauge. and it has one plug in to it. and the ground for the gauges is in the wire plug and everything else works so it cant be the grounds.

[Dave Severson]

How about the ground on the sending unit?

If it's ok, then you could remove the sending unit and check it with an ohmeter.