As the title states my ‘79 Coolant temp gauge quit working. I just had the radiator flushed and new coolant so probably a coincidence?

Old coolant was clean and radiator is sludge free.

Is there a way to test the sensor with a DMM?

Thx!

 

I did a little digging on the internet and found some instructions on how to test the Coolant Temp sensor with a DMM. I have copied and pasted the instructions below in case someone else here runs into the same issue. Hoping it's the Coolant Temp sensor and not the Temp gauge!

• For the testing process you will need to run the engine.
• Let the engine run to allow the engine to get up to running temperature.
• While the engine is running you need to be continually checking the digital ohm meter.
• You are looking for readings that are more than 200 ohms in variance between a cold and warm engine.
• If you do not see anything that is more than 200 ohms in difference, the coolant temperature sensor is defective and will need to be replaced.