Hi all, so I purchased a 2012 dodge Avenger, and I noticed on very hot (110+) days it starts to creep up above the middle, only to come back down as it starts moving, which signals to me it’s a fan issue. I disconnected the coolant temp sensor, and noticed that only 1 of the radiator fans turns on. What can this be?
Next time it is starting to overheat, pull over and see which if any of the two fans are spinning. From what I can tell, the PCM computer decides when to turn them on, and at what speed. Air conditioning refrigerant pressure, engine coolant temperature, and if automatic equipped, the automatic transmission temperature. The fans should come on at low speed when the engine coolant reaches 228 deg F, and high speed at 232 deg F. There’s relays involved with the fan operation located in the power distribution center. They’re controlled by electronics in the TIPM. There’s two fuses in the TIPM involved w/the fans, so check those. I don’t see reference to one fan spinning and the other not, so maybe the one not spinning has a failed fan motor. It appears the way the fan speed variation is done , low speed the motors are connected in series, high speed, in parallel. The fans are best checked using a scan tool. Otherwise you’ll have to secure a wiring diagram and test for proper voltages at the various spots. If you have ground and power at a fan motore, and it doesn’t spin, pretty easy to know what to do about that of course, so that may be a good place to start. Note that if one fan motor isn’t working, b/c of the series configuration used for low speed, it could prevent the other one from working too in the low speed mode.