Hi. Had our first really hot day today in uk and I noticed passenger side vents had colder air coming through them than the drivers side. This includes the centre, vent by side window and rear passenger vent. All three vents on drivers side were not as cold. Is this a collibration issue or ac issue. Thanks. Dave

 

model/year? most models have "doors" with actuator motors that route the air. Likely one is not opening/closing - could be motor, calibration (sync'ing) or as simple as a disconnected connector rod from the motor to the door.

 

Opps

It's a 2003 xc90. Read loads of posts including ones on other cars. Most say it is lack of gas in ac unit. Others say it's the climate control unit.

What you think

 

My Volvos are all designed to be hot on one side and cold on the other. So in a case like this, one would assume the control system is not obeying your commands, and the amount of hotness and coldness available are basically normal.


So yeah, the controller interface could be faulty, but it's not advertising an error, it seems more likely that the physical stuff behind the scenes is the real culprit. It's not easy to interrogate this digital stuff. You might be able to with Volvo Dice but I don't use it.

 

If you suspect low freon pressure as the reason for lack of cold, listen to the compressor - if its cycling regularly in a short duty cycle (say less than 5 seconds) then its likely low on pressure. Otherwise you need to measure the pressure on the "low pressure" port (this is on the return from the firewall back to the compressor. Buy a charge kit with a pressure gauge - pressure should be in the 40-50 PSI range with a full charge depending on air temp. If its below 20 PSI time to add a charge. Note you measure with the AC Running. If its cycling then you need to jumper the lower pressure sensor (also on the return line from the firewall to the compressor). I'd start with checking the AC charge since its something can be done as a DIY. Some good youtube vids to watch first.

 

I had a similar problem last year and actually found that warm air was coming from under the passenger seat and the driver seat. It was quite moist and I found the source of the problem was a blocked drain and the drain tube had somehow disconnected itself.

If you run the AC, does the condensed water drain under the car? Once I put a wire through the drain and reattached the tube, the whole system drained and started working properly.

I originally thought it was the doors not working properly. The hardest part of the fix was pulling the carpet back in the passenger foot well. It was very wet under the carpet foam and took several days to dry out.

It has been fine ever since.

Good luck.