Help with Temp guage
 

I have a problem with my temp gauge. I have 2 GM gauges and one Repop...same problem. I have had 2 sending units....both are suppose to be for gauges. My problem is that the needle goes to the Hot side. I just put the new Repop in and soon after I started my truck it went Hot. Any help is appreciated.

454 with aluminum heads.
Factory gauges.
Painless wiring.
.......

Sounds like the green wire that runs from the sending unit to the gauge is probably shorted to ground somewhere. If the wire is shorted, the needle should move to "H" as soon as you turn your key to the "ON" position even if your engine isn't running.

Try unplugging the wire from your sending unit, and then turn the key on. If the gauge still goes to "H" then the wire is probably shorted. If the gauge doesn't go to "H" then your sending unit is most likely bad.

:agree: if you have a continuity tester you could check the wire to ground to see if it is grounded out and then all you would have to do then is find the short :rolleyes:

Exactly. Folow the wire from the firewall to the sending unit. It is probably melted on an exhaust manifold or something.