Technical Temp gauge and bypassing the ballast resistor

Hey guys,

Quick question, has anyone ever ran into an issue with their temp gauge after running a distributor that needs you to bypass the ballast resistor. I changed over to a ProComp dist, and now my temp gauge doesn't work.
If so, did you just add cut the wiring from the gauge and add in a ballast?

Thought I'd ask before I start cutting wires to only find out it's the gauge. I'm getting the proper resistance from the sensor.

Thanks

 

I've had the temp gauge in a late 50s chevy go bad all of a sudden....something broken inside it.

 

Jim,
What testing did you do to determine it was the gauge? Or did you just swap it out and it worked? Which is a viable troubleshooting practice.

Thanks

 

sometimes it will come back to life if you give it a whack....

Check for voltage on the pink wire with the key on, check for resistance on the green wire. If it has that, then the gauge is not working. I think there's a rivet in there that has a tendency to break, among other things.

 

I assume this is in your 58 Belair. Check that you have 12v power to the IGN side post of the temperature gauge. Then take a jumper wire from the SENDER post to ground. When energized, the pointer should go all the way to hot. That gives you a basic continuity test.

 

Thanks Morris,

After testing like you suggested, the gauge turned out to be bad. Swapped it out with one out of another dash.

 

They can lose continuity. Actually, several things can happen, but if the coils are intact it can likely be repaired. Also, as a note to future readers, the FUEL GAUGE works in the opposite sense: grounding goes to Empty and open circuit goes to Full.

 

Is the temp gauge somehow wired to the ballast resistor? I'm not quite understanding why the two would be related.

 

The only connection should be indirectly, through the ignition switch...and only to the "hot" side of the ballast resistor, not the coil side.