Hey
I have a 1994 E320 Sportline and the heater is stuck on.

I was driving my car today with the A/C on and i stopped to wait for a friend. I started her back up and then i realized my A/C was stuck on heater, None of the lights go on when i press the buttons, but the fan still blows, checked the fuse box, no blown fuses.

If anyone has any ideas, any help would be appreciated, coz its the middle of summer, and i cant go without my A/C in 36 degree Celsius heat.

 

I've just gone four rounds with my 83 300sd's heater issues. The first thing I had to fix was my mono valve... the more I checked around the more I realized that this is a common problem with mercedes climate control. When the mono valve fails it causes a variety of symptoms ranging from full heat all the time to no heat to sporadic works-when-car--is-idling-quits-on-the-highway. I've noticed the heat always seems to fail in the winter(as in my case) or go to full heat in the summer and it can quit working all of a sudden as it seems to have for you. Here's a link to the part I think you might need... hopefully someone will chime in because I'm not familiar with your model and I am just guessing based on my own experiences. Hope this helps. http://www.autohausaz.com/search/product.aspx?sid=o4ylz145xkdrz3ym2csso355&makeid=8 00016@Mercedes&modelid=1195567@E320&year=1994&cid= mono@mono&gid=6860@AC%20%26%20Heater%20Control%20V alve