check the fueses check fueses
Blower motor switch. Put it on High and it will blow when sitting still with the engine running.
Probably the blower motor, wiring to it or control switch
Recommend you check the blower motor resistor.
It is either the blower motor control switch or the blower motor resistor pack. More than likely it is the resistor pack. It must be replaced or just live with it until it fails completely.
If you are referring to the blower motor speed control, and you only have one speed, then the blower motor resistor pack is defective and must be replaced.
Engineering
faulty blower motor resistor
you need to repleace the blower motor resistor under the das on the passenger side
30 amps.
Loose connection or blower motor is bad
Simply put... It's because the failure mode of the blower control module is electric power on! (even with ignition off)... Disconnect the battery, or better... find and remove the 30 amp blower fuse. Remove and replace module with serviceable unit. Reinstall fuse or reconnect battery. Good luck! Note: If the blower is noisy at high speed or in cold temperatures, (if it vibrates or rumbles and squeals), now is the time to change it!
When that happens on a Chrysler Town and Country with auto temperature, the blower motor power module has failed. It is also called a blower motor resistor.