Detail: Hi: I read your answer to the problem with the 1999 Mercury Mistique temperature gauge. I'm having a similar problem. My temperature gauge is broken in the cold position. And, as far as I can tell, the radiator fans never go on. (The radiator fans are triggered from the same temp sensor as the temp gauge uses.) When I disconnect the sensor when the engine is running, the radiator fans turn on (suggesting hot reading) but the temp gauge is still stuck in the cold position. I've replaced my thermostat, and temperature sensor. Any ideas? 1998 Mercury Mistique 2.0, 4cyl engine thanks, Eric
Solution: Very correct the ECT is a 2 wire thermistor,when coolant temp increases, the resistance andsignal voltage decrease,If you disconnect the sensor the fan goes on, you just trouble shooted the vehicle cooling fan switch, If anything the signal to the gauge itself may be non-op and not getting to the indicator, try this with vehicle at warm up temperature if you turn the A/C does the fan turn on.it should if it doesnt the power juction box (fuse and relay in engine compartment should be checked, for any opeen fuses, By the way the guage information is from the PCM , Hi, a 6ya Mechanic can help you resolve that issue over the phone in a minute or two. Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US. click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need. Goodluck!