Re: Engine Temperature Guage Inoperative - Where to Start?

Posted by HH56 On 2013/1/14 18:57:00

The 48-50 gauge is electric and stays at the hot side when the key is off. They don't use the typical or common resistance type sender though. As soon as the key turns on it should go to the cold side. If it does not, likely causes are a bad or wrong sender, an open wire between gauge and sender or a bad gauge.

To test, have the key off and ground the wire at the sender. Turn the key on and immediately watch to see if the gauge moves to cold. During the tests do not leave the key on with wire grounded any longer than the time it takes to move the needle.

If it moves, you have a bad or wrong sender. If no movement, repeat the process only grounding this time at the gauge terminal on the wire going to the sender. It should be the terminal with just a single wire going into the harness. The power terminal will also be connected on the back of the cluster to the oil and gas gauges so be sure not to ground that side. If gauge moves this time then a bad wire to sender.

If it still doesn't move then assuming the other gauges have power and work, you have a bad gauge.