Clean the Climate Control on XC90 /any Volvo Heater blows Hot then Cold then Hot then Cold air

My Volvo XC90 was blowing hot air then cold air then hot air then cold air. You GENTLY clean the dust from the resistor on the CCM ($200 part from FCP Euro, cheaper elsewhere) and it allows the resistor to accurately control the blend doors.
I reckon any car would benefit from a gentle cleaning of the resistor since every car out there has the same basic idea of a resistor measuring air temperature (based on my meager google searches). It just changes where it’s located.
I couldn’t find much info on the web about this specific issue. I saw one of Peppermint’s videos with a similar problem and was inspired.

[@PetesProjects0]

Thank you for the clear explanation of the problem. That completely matched my situation. I cleaned it and SHAZAM it is working again!

[@chrisirish3460]

Thanks, I have the same issue and had no idea how to fix it other than replacing the sensor, but I guess ill try this first.

[@coreymills1520]

Why it never dawned on you guys to just use a keyboard clear air in the can spray and just blow in there with that it works I've tried it numerous times for different people it works use the keyboard spray you can get that at Staples Walmart anywhere you don't need none of that other stuff

[@HereXEG]

I cleaned mine and it still does it. I found that if I move the temperature nobs back and forth and don’t land on all the way up or all the way down then it stays at that setting.

[@awaisdon2868]

Have you managed to get it fixed now?

[@timothyliddiard5034]

A brushpick works great. That is plastic tooth pick with a tiny brush one one end.

[@rogercondray7119]

Same issue and it drives me nuts. This didn't fix it. Switch out the part with another from the salvage yard, still not right. Works some times. I turn knobs this way and that, turn off this and that, hold my tongue this way and that.

[@cathcolwell2197]

thanks. too much talking