Hello, I've got a problem with my 2006 S40 T5, radiator fan just won't turn on at any temperature, so engine overheats, it only spins when I turn on the AC. I even bought a new aftermarket one that works well, but still, only when AC on, and it cools the car better when in hot temp at the AC. What could it be?

 

Welcome to the Forum!

First thing is to check the coolant level. Low coolant in this car produces some strange behavior.

I would guess either Coolant Temp Sensor or fan relay. Although I've not had problems with my 2005, the fan on my 2001 would act strange with a CTS issue. Now I suggested the fan relay because some cars have either a high/low speed or a separate circuit for the cooling vs A/C. Not sure how the 2006 is setup yet.

 

Thank you very much for the quick answer Hudini, I've already sent this information to my Volvo dealer mechanic (which I don't know why isn't able to find a solution for this) or if he isn't able to fix I'd do it myself.

Again thanks!!!