Originally Posted by
dedwards0323
I've got this phenomena going on with my fan speed. What I've noticed is that this only occurs when I have the A/C on. When only using heat or ventilation, the fan speed seems to work OK. So I'm leaning towards an A/C problem (probably a sensor indicating low refrigerant level) which would switch off the fan/system. Once warm weather season comes back, I'll have the system checked. Might be low refrigerant; might be a bad sensor.
You'll be chasing this for a long time. The service procedure is if the fan speed is not working according to its indicated function, Chrysler first replaces the fan resistor. If that doesn't fix it, they replace the control head. I recommend you read/review section 24 of vol3 service manuals titled HEATING & AIR CONDITIONING, maybe you'll have a better understanding of this system. Good luck!