Heater stuck on hot - drivers side only

[reggit]

Right oh knowledgeable people...

The heater on my V70 is playing up, passenger side works as it should. Driver side is on heat if the temperature is set to anything but cold (blue).

Vida shows no errors, bar the AQS and the damper motors appear to be moving as expected.


Sometimes there is a mechanical knocking from under the dash. Suspect something is broken in the heater, but absolutely no idea where to look.


I'll be grateful for any pointers. Cheers

[cheshired5]

Have you done a CCM recalibration in Vida?

[oragex]

Try the recalibration as mentioned above. One side is reading the cabin temp sensor, while the other side is extrapolating from the other's side temperature button position. Blow some air onto the temp sensor as well (the thing behind the grid near the heat button, don't touch physically)

This temp sensor may also have an issue but try cleaning it in the first place https://www.youtube.com/watch?v=riC13zbjdgg

[reggit]

Been working away so wasn’t near the car when I posted. Haven’t tried the recal as I can see the damper motors to be approximately on the same position between the 2 sides and moving as the temperature changes.

Back home now, so will try a recal later as it can’t do any harm. It’s the physical knocking it’s making that makes me think something may be broken internally.

[cheshired5]

Also, view the cabin temperature sensor reading to see if it is credible within CCM parameters.

[reggit]

Sorry it’s been a while updating this, not been using the car.

As expected, the recal in Vida didn’t have any effect. The motors are showing what I’d expect. I think a flap or something has jammed or broken.

Anyone know where to look?

Is the heater box reasonably easy to change if the dash is out? (Done that before on an old s60).

Cheers

[oragex]

This is how the CCM sounds when it's working, maybe it helps https://www.youtube.com/watch?v=cbFp7udMxks