Fan switch only works on high speed, resistor?

Hello,

This is common when the speed control resistor for the blower goes out here is the location so you can change it out. Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

Do you have a multimeter to do some testing?That way we can make sure its your blower motor resistor before replacing it.

Also do you have auto climate control or manual temp control?

How do you know its bad-could be a fuse/control switch/relay problem

Find the blower motor- turn heater on-bang on it a few times-did it work?

Its behind right side of dash on the HVAC assembly.

The blower motor resistor is mounted to the rear side of the HVAC housing on the passenger side of the vehicle.

Disconnect and isolate the battery negative cable.
Open the glove box door to gain access to the blower motor resistor.
Pull out the lock on the blower motor resistor wire harness connector to unlock the connector latch.
Depress the latch on the blower motor resistor wire harness connector and unplug the connector from the resistor.
Remove the two screws that secure the resistor to the HVAC housing.
Remove the resistor from the HVAC housing.

Yes, it sounds like your blower motor resistor is out this is located in the heater box near the blower motor. (speed resistor) please let me know. If thats okay the switch has gone bad but to be sure here is the wiring diagrams below so you can see how the system works.

Here are some diagrams (below) and some guide to help you test to confirm the problem and get it fixed:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Please run some tests and get back to us we are interested to see what it is.

Cheers, Ken

Hello,

Yes, this is a dealer item only.

Please use 2CarPros anytime, we are here to help. Tell a friend please.

Cheers, Ken

This sound like a textbook example of a blower motor resistor failure. The resistor is what controls the speed of the motor, simply put the switch sends power though different curciuts in the resistor which changes the speed. The lower three settings slow the electicity, which slows the motor. The top setting is a battery voltage "pass through", the high speed will eventually fail is the resistor is not replaced.
The resistor is located behind the glove box and fairly easy to replace.

1) Disconnect and isolate the neg battery cable.
2) Open glove box door to access resistor.
3) Pull out lock on blower motor resitor harness
connector to unlock the connector latch.
4) Press down on the latch on the blower motor resistor harness connector and dissconnect the wire harness from the resistor
5) Remove the two screws that secure the blower motor resistor to the HVAC housing and remove the resistor.
Reverse to install, torque screws to 17 in-lb (2 Nm)

This is the R&R from my database.
The resistor may be available from you local parts store but check the price at your local Jeep dealer as well, sometimes with electrical parts they are less expensive at the dealer and even if you buy them and install them yourself Chrysler parts come with a 12 month warranty.
Let me know if this helps.

Dan