I have a 73 and cannot get the temp gauge to work. I grounded the green wire and nothing happens. I ran a seperate ground to the center terminal and same results. I thought that maybe the pink wire had no power so I put 12 volts to the pink terminal but s> till nothing. I changed the gauge and all the results are the same. Also the fuel level gauge wont read, yes it has gas in it, I shorted the gauge and it works, I pulled the tank and the sending unit functions and the ground is good.

> Thank you, Butch York.

http://repairs.willcoxcorvette.com/corvette-temperature-gauge-testing/

I had found a youtube video on troubleshooting a C3 Corvette temp gauge, but I can't find it again now.  It did show some common problems and what was causing them.  My temp gauge always stayed around 100 degrees, and the video indicated that an insulator on one of the connection posts may be bad.  Haven't had time to pull it and check yet.

I found the troubleshooting video for the temp gauge: https://www.youtube.com/watch?v=A9iPeiu9Y8M