Hello,
Just got 2006 Montero back from mechanic and he could not solve this problem. The electric (auxiliary) fan sometimes comes on when first operating vehicle, then never comes on again.
Mechanic Notes:
-replaced coolant temp sensor
-back tested sensor for fan and signal to and from the PCM, intermittently no signal from PCM
-recommends replacement of PCM (not available!)
-says vehicle maintains correct temp without this aux fan (I am concerned it may shorten the life of the AC compressor or overheat in traffic)

*I have TWO, 2006 Monteros, should I swap PCM and see if this solves problem, or could this lead to more problems?
*Should I send the PCM for repair?
*Is the problem something else mechanic didn't think of?

Thank you in advance for your time!!
Rob

 

Try to check the aux. fan resistor it may be faulty.

 

Thank you for your input! Can you please tell me how often your electric cooling fan comes on/off on a hot day? Does it consistently cycle on/off?

 

Aux. fan comes on as soon as a/c is turned on and then will cycle every 5 min. more or less.

 

I'll check with no a/c on how often it cycles as soon as i have a chance.