My SLK 230 will fog up bad inside the windows if I try to defrost the windsheild. I turn on recurlate and heat full.

What is causeing the moisture??????

 

You have water getting in the cab, Clean your drains, to front to back,
rears are in the trunk near rear window corners, fronts under black bit the wipers pop up through, Use strimmer wire ( weed whacker ) and push it down untill it pops out of the bottom, you may have to pour some warm water down the pipe same time if its really blocked.

 

Thanks, I'll try it this weekend.

 

Plus, if your windows are fogging up, you don't want recirculated air from the inside of the car. You need fresh air from the outside. When the Defog setting is on, it actually uses the air conditioning to dry the air out. Make sure you are not in ECONONMY mode or the AC compressor will not turn on.

 

Yes very true

I missed that bit of the post

 

Don't use Recirculate! Make sure your air conditioner works properly. In defrost mode the air is run through the A/C evaporator to dry, then through the heater core to heat it so you will have dry air hitting winshields. Change your cabin filter as well..