Tech Tip: XC60 HVAC blower always on

May 14, 2024
Volvo owner came into a shop complaining that their HVAC blower ran constantly.

The owner of a 2010 Volvo XC60 took their car into the shop complaining that the HVAC blower ran all the time, even with the key in the off position. He had to pull the blower fan fuse to keep the battery from going dead.  

Case details

ALLDATA Tech-Assist was called to help get the diagnosis started. The Tech-Assist consultant said to check for voltage on the VIO/BLK wire going to the fan control module (blower resistor). That is the control circuit from the HVAC control unit. With the key off, there should be no voltage there. 

The technician performed the inspection as suggested and found that there was voltage on the VIO/BLK wire. The voltage dropped and the blower stopped when disconnecting the climate module. As it turns out, the climate module was providing constant voltage to the blower. 

Confirmed repair

The technician replaced the climate module and checked to make sure the blower motor turned on and off normally. It did. Issue resolved!

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