My husband recently replaced the A/C Compressor in my 1999 MBZ 320e. Since he finished, the passenger side blows nice and cold. The driver's side? Not at all.
He says that there was something about codes.
Can you tell me if there is a code that we could check or adjust that might address this specific issue? (I live in Arizona. Working A/C is absolutely imperative. Please help!)
Refrigerant Charge is NOT an issue. It was evacuated & weighed in. My husband is a master residential HVAC service technician. He understands the concepts of air conditioning. He knows how to work on car A/C. (He doesnt like to, but he knows how to do it) ... but a Mercedes is a different beast.
Please help.
Thank you.

Please forgive me if I'm duplicating an already asked question. I've been searching for hours, and just found your site. I can't stay awake another second, so thank you in advance for your help and again I'm sorry if I am being redundant.


Your W210 should have what is called a duo valve in the engine bay. It is on the passenger side. This allows for hot air to circulate in the cabin. Sounds like one of these is stuck. There is one in the passenger side and one on the driver side. You can remove them and try to clean them. Or remove them and switch them around. The hot should work on the driver side but not on the passenger side if you switch them.

Try that and let us know. If cleaning the duo valve doesn't fix the problem, you will need to replace it. A used duo valve should do the trick.

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