A/C working on driver's side only - 2002 XC70

green122 · Post by **green122** » 15 Jun 2009, 13:36

The A/C is not working on the passenger side even with the temp control switch set to the lowest temp on the passenger side. Driver's side A/C is fine.

I have used a code reader from BSR in Sweden to read the DTC output and there were no codes saved for the ECC. I then removed the glove box and saw that there were 3 servo motors on the inner passenger footwell side of the ECC unit. The upper one controls a large white rotating disk that I assume is attached to the unit that distributes the air to the different areas on command from the control unit. I tried different combinations of vent settings and this control motor responded to each of them. I also tried heat and cold and found that the lower left motor responded to this and I assumed that it was opening and closing a vent to allow heat into the system. I could not see any evidence of movement of the motor on the lower right but there wasn't anything to see moving so I don't know how significant this is. I am not sure it is the vents but I thought it might be. Does anyone have any info on the ECC that might help me with this?

Thanks in advance for any help.

Gary

Post by **vegasjetskier** » 15 Jun 2009, 15:11

According to VADIS, the lower right damper motor controls the defroster. Do you feel cold air coming out of the passenger's side defroster vents when the AC is running?

green122 · Post by **green122** » 24 Jun 2009, 18:32

I finally gave and took it to the dealer. It turned out to be low on refrigerant! I had looked at all the more complex issues and it brought back to me how important it is to start simple. The frustrating part is that I checked it with one of the simple gauges that you get with the R134a kits and it had checked out. That was the most expensive charge I've had.

Thanks for all your help.

Gary

Post by **vegasjetskier** » 24 Jun 2009, 18:36

Hmm. To my mind, low refrigerant does not really explain why the driver's side was cold and the passenger's side was not. If it was only refrigerant, the temp should have been the same on both sides, just not cold enough.

green122 · Post by **green122** » 25 Jun 2009, 04:53

I know it doesn't make a lot of sense but there it is. I may find out over time that it is a flap motor but it is working fine now. Don't mess with success!

Post by **VCA** » 25 Jun 2009, 06:04

vegasjetskier wrote:Hmm. To my mind, low refrigerant does not really explain why the driver's side was cold and the passenger's side was not. If it was only refrigerant, the temp should have been the same on both sides, just not cold enough.

I can think of one scenario: the air stream is split just after going through the evaporator. The driver's side is on the inlet side of the evaporator, so the driver's air is cooled; because it's low on refrigerant, the gradient is much more sudden than it normally is, so the passenger side gets much warmer refrigerant than normal, and so gets little cold air. Looking at the parts diagrams, this may explain it...