Fan speed control

I recall seeing a thread about this on here somewhere, but couldn't locate it.

On our 2004 with 133,xxx miles, 2.4L manual, the fan speed for the AC and heat is acting up.

With 4 speeds, 1 and 2 do not activate the fan at all, but speeds 3 and 4 work normally.

I'm thinking it's the fan switch ... any thoughts?

It might be the resistor trio (speed controller). Conventional speed controllers use 2 or 3 resistors to provide the lower speeds. Possibly one of the low speed resistors is broken or has an open circuit.

I am not sure is your Jeep uses this type though.

It might be the resistor trio (speed controller). Conventional speed controllers use 2 or 3 resistors to provide the lower speeds. Possibly one of the low speed resistors is broken or has an open circuit.

I am not sure is your Jeep uses this type though.

Thanks, I guess some underdash diving is in order. If it uses the resistor system, where would they be located?