2005 XC70 ECC fan speed control working intermittently

[Stoneworks]

Over the last few years the blower fan speed control knob has been having episodes of not working very well, and getting worse. I can rotate the knob and it won't do anything, or doesn't change the fan speed with each click. The led still seems to indicate the fan speed correctly. The last good Volvo tech that worked on the car said the speed control switch? was going bad and he could only replace the entire module, about $3k plus labor. He did say there was a thread here where someone replaced the switch and even had the part # for the switch from Mouser, Digikey, or such. I have been searching for any info for a few hours now without finding the right info, so now I am asking for help, please.

Today it was close to 100f when we got in the car to go to town, and no blower! I messed with it awhile and when I pressed on the knob then rotated it worked well enough to adjust the fan speed. It does seem that the hotter it is the more it acts up. My wife has been wanting me to deal with it and is now getting adamant.

Any information would be appreciated.

Thank you,

David

[Stoneworks]

Wow, over 150,000 views in 2 months for this post. Anyway, I wanted to update it with my fix. All I did was vacuum out the sensor and it is 99% fixed. The sensor hardly had any stuff in it so it is very sensitive to any dust or fuzz. I plan on blowing it out with compressed air to see if that takes care of the last bit of hesitancy it has. Way easier than taking anything apart. Weird how it totally disabled the control knob.