unfortunate result of US market gimmick :-(
Unfortunately yours is a common an not inexpensive problem with these cars. These systems are very hard to diagnose by the DIYer - you are best taking it to a Mercedes specialist to at least get them to tell you what the problem is.
If you are lucky, it will be the control panel (where the wheel and buttons are). This shouldn't set you back too much.
The less fortunate option is that the potentiometer is buggered. This is the little motor that opens and shuts the valve for cold/hot air. While the part is all of about $40, the whole dash will need to come out to replace it. It cost me about $1500 for this repair [:0] (including aircon recharge), and it took the repair shop (a very reputable MB repairer) 2 goes to get the diagnosis right (so imagine how long it's going to take you!).
There are other possibilities, but these are your most likely I think. Other people may have better input to this discussion.
Unfortunately yours is a common an not inexpensive problem with these cars. These systems are very hard to diagnose by the DIYer - you are best taking it to a Mercedes specialist to at least get them to tell you what the problem is.
If you are lucky, it will be the control panel (where the wheel and buttons are). This shouldn't set you back too much.
The less fortunate option is that the potentiometer is buggered. This is the little motor that opens and shuts the valve for cold/hot air. While the part is all of about $40, the whole dash will need to come out to replace it. It cost me about $1500 for this repair [:0] (including aircon recharge), and it took the repair shop (a very reputable MB repairer) 2 goes to get the diagnosis right (so imagine how long it's going to take you!).
There are other possibilities, but these are your most likely I think. Other people may have better input to this discussion.
