My temp. gauge needle on my 73 454 4-speed is froze as shown. Car has never overheated, so my guess is I need to replace the Temp. Gauge, and while doing this probably the temp. sending unit also

since they ae both original equipment on a car with 50,100 miles that I have had for 49-years.

 

Before buying a new temp gauge check your wiring, if everything looks good, then search the internet for a step by step testing procedure. Taking out the temp gauge is no walk in the park. If you find that you have to purchase a restoration gauge, test it prior to installation. Again, you will find that most of the guys on the Forum don’t trust the restoration parts 100%.

 

check wire at sender
remove and watch gauge

check wire for issues

 

System is shorted to ground somewhere. That indication means zero ohms in the circuit.

How To Troubleshoot Temperature Gauge Issues:

Problems with your temperature gauge could be caused by the gauge itself, sending use, fuse, or wiring. Here are a few areas you can check to help troubleshoot the issues you may be having. NOTE: Perform the following procedure with the ignition key turned to the “on” position.

1.Temperature Gauge Sending Unit: Remove the wire from the temperature-sending unit located on the engine (typically a dark green wire). Then connect the wire to a good ground. You can do this by using a jumper wire. Check the gauge, if the needle points to “Hot”, replace the sending unit. If the needle does not move, remove the same dark green wire from back of the gauge and connect a jumper from the terminal on the back of the gauge to a good ground.

2. Temperature Gauge: Check the gauge if the needle moves toward “Hot”, the wire from the gauge to the sending unit has an open or bad connection. If it does not move, connect a test light by grounding one end to a good known ground and the other end to positive side of the gauge (typically a pink wire).

3. Fuse: If it does not illuminate, ensure the gas gauge fuse is good. If the fuse is good, connect a jumper wire between the ignition switch and the positive side of the gauge.

4. Wiring: If the gauge now works, replace the defective wiring between the gauge and the ignition switch. If the test light illuminates there is 12 volts present, replace the temperature gauge.

 

Thanks for the info and the video link to Wilcox Corvette. It gives me an idea where to start my trouble shooting.