climate control
 

I think I can give a clearer picture of the problem now. When the car is turned on the ac comes on and works perfectly for 15-30 seconds, then it defaults to defrost which is hot. Also when the car is turned off the motor on the blower continues and obviously turns off later. The light behind the led is no longer working. We want to fix this but Star Service is out of the manual for the 1993 500SL not sure about the AllData and one thing I do know is if you don't have an idea of what is wrong you could pay a lot of money and still not have it repaired. I would appreciate any help.

Forgot to say that the unit never goes off, so we always have the hot air from the defrost coming out except for the few seconds at the beginning. We do use the "O" button to no avail. Also ran the diagnostics got codes and erased but did no good there. also since we don't have the codes meanings had no idea what I was looking at. One code we got was FF 1.

On "the other forum" is a very useful pdf of fault codes as reteived by a commercial scanner tool. It might be helpful as it does list error codes for the AC system. Index to your model year and AC.

http://www.benzworld.org/forums/r129...?.#post2342164

Your symtoms seem as though your CC unit is stuck in the REST "residual heat" mode. After the key is turned off, the blower and aux water pump continue to run to heat the car until the coolent temp drops to below a useful temperature.

These CC units are known to have the switches go bad due to solder fatigue. They can often be repaired by resoldering the switches to the printed circuit board.


http://www.benzworld.org/forums/r129...?.#post2342164