Gas & Temp gauges

[rust bucket]

Cannot get my gas gauge or temp gauge to work.
Have power to everything. replaced the instrument cluster voltage regulator and still nothing. Replace temp sending unit also. Unhook the ground wire to the instrument cluster and both gauges peg out at top end. ran jumper wire from temp sending unit and gas sending unit still nothing.
It has me puzzled, don't know must about this electrical stuff, NEED HELP to figure this one out!

[rust bucket]

For got to state that this is for a 1965 f-100

[Toyz]

What happens when you temporarily ground the sender wire(s) with all else hooked up ?
Paul

[rust bucket]

Just tried grounding sending wires, nothing happened. tried grounding with wire unhooked from sending unit and with wire still hooked to sending unit, nothing. this is the gauges on a custom cab dash if that helps any.

[bruceandersson]

The pegging of the gauges after disconnecting the ground is very strange. I'd get a copy of the wiring diagram and make sure everything is hooked up correctly. It seems like you have some type of short or switched wires. Wiring issues are always fun to track down as it is tedious to test each connection for continuity, but that's what you probably need to do. Verify the correct voltage to the dash unit, the correct coming out of the regulator....

[Toyz]

The fact that both senders have the same effect points toward a problematic the panel. If you haven't probed the sender wire with a test light, that would help verify the regulator and regulator voltage supply. With the key on, a grounded test light hooked to the wire removed from the sender should pulse. If it does not, check the voltage regulator supply and ground. If 12 v supply proves out, and a jumpered ground to the regulator makes no change, the regulator is defective. If you get the pulsed indication at the test light, the gauges and/ or wiring between regulator are likely the problem.

[rust bucket]

Thanks, will have to see if i can find a test meter this weekend. will let you know how it goes