2008 v8 xc90 climate control
 

The drivers side climate control blows cold air ( def, vent & foot) rather than heat. Also drivers heated seat not functioning. Passenger side working perfectly.
Checked drivers side heated seat fuse and it was fine (replaced it anyway).
Since the heated seat stopped working at the same time it seems different than other similar issues and fixes posted here.
Any thoughts ?

First try to disconnect heat seat control module. It a small block under the seat.
Just google "volvo heat seat control module" and you will see pictures how it looks and where is placed.

XC90, no seat heat
 

I have the exact same problem on my 09 XC90 V8 R design. I am unable to change the AC/Heat setting on the drivers side and the seat heat quit at the same time. Fuse is OK. Does anybody know what the problem is and how to fix it?

Seat Heat Module failure 09 XC90
 

I fixed the problem with a replacement seat heat control module, part #30795503. It worked for two months but has gone again. I suspect that something in the seat heat wiring is causing the problem. I am going to replace it again and keep the seat heat off. At least I will be able to have the drivers side heater and ac working.