I know it is a very common problem, but I cannot seem to find a solid answer as to why or what could be wrong with it. My CCM does not light up and it is very quirky when first used EX: The fan speeds change rapidly to different settings randomly. This will usually stop after awhile. I have read a lot on the resistor, however, Ive seen a lot of people replace it and continue to have the same problems. What would be causing it to not light up and function improperly?? Any suggestions??

Car: 2001 S40 1.9t has automatic climate control functions.

TIA all

 

I have heard some mention broken solder joints in the climate control unit. This would explain the behavior. As the unit warms up and metals expand, the connections press together but when cold they separate and are intermittent. I think my son's '01 S40 has something like this going on.

 

I can't comment on the lack of lights but I did have the same symptoms as you re: erratic fan operation. Many have suggested that this is due to oxidation of the potentiometers in behind each of the temp and fan dials. Some have reported success in spining the dials back and forth quickly about 20-30 times to clear the oxidation. If the oxidation has gone too far though you are stuck replacing the POTs. Not a big deal, as long as you can get your hands on two POTs and you know how to solder. I found two POTs from Mouser Electronics. See below for part details. They are about $2 each. The tricky part is that each of these POTs are calibrated in the factory so that the fan and temp dials behave nice and smoothly as you turn the dial. When you slam a new one in that has not been calibrated you may find that when you turn the dial you don't get a nice smooth progression of fan speeds for instance. That didn't really bother me as I set it to auto and then leave it well alone. Some degree of calibration can be achieved in situ though simply by very carefully bending the white plastic spindle in behind the dial so that fan turns off at zero and then turns on at 1. It just takes a bit of fiddling to get this right using a candle or lighter. Apply a bit of heat and then twist the spindle ever so gently. let cool and test. Repeat until you get it right.


#: 769-JSM1-12V-5
Mfr. #: JSM1-12V-5 Desc.: Automotive Relays Automotive Relays 15A 12VDC SPDT HI-CAP SEALED PCB

 

Hi Pierre!
I'm from Hungary,and i have the same phenomena with my Climate Controller on Volvo S40/2003.
In your post above you mentioned about erratic operation of the fan due to POT's oxidation. This is also proven personally by me.
You also wrote regarding replacement of POTs. Unfortunately the links given point to relays, not POTs. I tried to find appropriate parts for ages, but never found. Could you give me advice, where those POTs, that fit exactly can be purchased?

Thx in advance and best regards
George