Testing coolant temp sensor?

[Tylan]

Hey y'all, I recently replaced the instrument voltage limiter in my 74 duster because the temp and fuel guages were shooting up. I think the fuel guage is working now, but now the temp guage won't move at all. My initial thought was that the sensor or wire could be bad. I was wondering if anyone knew what ohm readings I should look for when testing the sensor?

 

[67Dart273]

Start by shorting the sender wire to ground and watch the gauge. Don't leave the key on for long. The gauge should shoot over towards the hot end

 

[RedFish]

A mechanical limiter sends a pulse voltage through the gauges. A solid state regulator sends 5 volts through the gauges. In either case and volts meter should show some voltage at the sender purple wire. If the water is somewhere between 180 and 210, sender resistance should be somewhere between 35 and 15 ohms.
You have white plastic engine harness connector. Sender wire and alternator wires routed through it. Those have been known to melt and short wires together. Look at it too.

 

[cudamark]

Start by shorting the sender wire to ground and watch the gauge. Don't leave the key on for long. The gauge should shoot over towards the hot end

Yup, if gauge now moves, replace the sender. If it doesn't check your circuit board connections on the back of your gauge cluster.