vincent52100

Good morning. I have a 2004 s500. The problem is that I can get a/c out the center vent but warm air comes out the side vent. Also it seems like the a/c has to be set in the low 50's to get it cool. I had the a/c checked and serviced. I've looked at several posts and it seems as though the problem is likely the duo valve. Haven't cleaned the duo valve yet. I did clean the valve on my 98 E430 and it seems to be very similar. Am I on the right track or am I missing something? Thanks

Here is some more info from some checking I did yesterday:
When checked the outside air temp was 51F.
I set the climate control on Auto with temp for both sides set at 60F. The wheel on the center vent was set to A. The results of checking the temp at each vent were:
Left side - 90F
Right side - 110F
Center - 80F

I then set it to 54F with the the wheel on the center vent still set on A with the following results:
Left side - 90F
Right side - 100F
Center - 80F

I then turned the center vent wheel all the way to the blue:
Left side - 90F
Right side - 100F
Center - 58F

I had the A/C checked at an A/C shop. He checked pressure, leaks etc. Everything checked out.

mrbobby

Been there done that, have the T-shirt. Hard to believe but your problem is likely the cabin temperature sensor which is located in the interior light fixture. Either the tiny thin wire is broken or the sensor is kaput. To my knowledge the sensor by itself is not available and you need to change the whole interior light assembly. They used to be readily available on eBay. No guarantee but this is what needed to be done to fix mine.

vincent52100

Thanks!

vincent52100

Well, tried the cabin sensor. Fixed the wire (don't know if it was broken or I broke it) but it didn't do anything. Pressed the REST button and wrote the codes down.
NR. 00 22.0
01 +0.0
02 +18.0
03 +44.9
04 +49.4
05 +10.1
06 +71
07 5.5 Bar
08 +17.3
09 +8.3K
10 2.64
Thanks for any help.

DrDoe

Perhaps your sensor is bad?
01 should not read zero...

01: Overhead control panel for in-car temperature sensor

vincent52100

Thanks! Ordered one with a warranty from EBAY. Fingers crossed.