Hello, my 580C coolant water temp dash gauge and my trans oil temp gauge have never worked. The gauges would respond (max out) when I grounded out the sender/sensor/signal wire, so I assumed the senders were bad. I replaced the senders, and the gauges still dont respond the way I expect them to. They seem to raise a little bit after engine is hot, but both are still showing in the yellow (Cold) area even after hours of heavy work. Any ideas? What kind of resistance gives the gauge a "warm" or "too hot" indication? What resistance do the senders give when hot? Maybe the gauges are out of spec? Thanks..
The transmission temp gauge is usually in the cool range. the only time it will come up is if you stall the converter for 5-6 minutes then it should go to the middle or hot side of the gauge. As far as the engine temp gauge, is the engine getting to 180 degrees were the thermostat should open or is the thermostat stuck stuck open and the engine is truley running cool?
mine had same thing try taking the wire off and see if any change then ground it if no change then you have bad connection to the dash units you need a new printed circuit board which you can buy from case with out buying the hole dash cluster
I had a similar problem, after replacing sending units and messing with the wiring, it turned out the thermostat had a small piece of rubber stuck in it holding it open, so it never got to operating temp. Replaced thermostat problem solved.