The temp guage on my Vette stopped working and I was going through my red GM shop manual for advice. Anyway, the Temperature Guage Diagnosis section tells me to connect a "J-24538-A Tester" to the sender wire and ground and look for a response.

My question is, what is a "J-24538-A Tester"? Is that a GM-specific tester, or does it matter?

RON

Hello Ron,

I don't know what the tester is, however, if your gauge isn't working then there are three things to check. The gauge, sender, and wiring. I test the gauge and wiring together at first. Do this by grounding the temp wire that the sender is attached to. Have a helper view the gauge. It will peg to the right, full hot. Don't leave it like this as it is hard on the gauge. Just touch the wire to ground momentarily. To test the gauge seperatly, use a 9 volt battery on the terminals. The gauge will go about 2/3rds hot. Check the wire continuity with an ohm meter. Finally, test the sender with an ohm meter. The hotter it gets the closer to ground the meter will show.

Alex