'05 T6 XC90 Blower control knob not functioning

[sebastiaan333]

Hi all,

Bought a used '05 XC90 T6 last week which looks to be in good order but has a few niggles here and there. One of them is the fact that the control knob for the a/c fan speed stopped responding the day after purchase. A/C works beautifully with no strange noises or smells. All the other buttons on the climate control panel function perfectly, except for the fan speed knob.

The led lights above the knob light up, but twisting the knob has no effect.

I inspected the engine compartment and driver side door fuse boxes and everything checked out.

It's not a major issue as the A/C quickly and quietly brings the cabin down to the desired temperature, but I'd like to take care of it nonetheless.

Thanks for your time,

Sebastiaan

[tailor]

It does sound, on the surface like the blower motor resistor is faulty, as the problem does present itself in this fashion. My experience was that the blower motor would continue to run loooong after the car was turned off, also running the battery down. The temporary fix was to pull the fuse for the climate control at each long/ overnight stop.

I resisted the ( excuse the pun ) repair up to the point when the motor no longer ran at all and I was fed up with the situation.

The official repair is to remove the dash which is 10 hours labour, due to brilliant design, to gain access to the motor and resistor. There is another way which is here, https://www.matthewsvolvosite.com/forums ... 7&p=282704
, that was to break off the last tab for the blower motor, thereby allowing the motor and resistor to drop.
I chose this method and replaced both the motor and resistor at the same time. Due the fact the blower motor can draw too much current, it will take out the resistor. The safe approach would be to replace both together because you do not want a faulty motor destroying a good resistor as soon as you put it in.


Tailor