Found this on the site, sounds like I, may be on the right track?




Quote:
Originally Posted by ickrulzz
My '05 does something similar sometimes. It's been a while but the heat will come on and the blower is full blast no matter the setting. Hitting the dash will stop it half the time. It hasn't done this in a while. It always seems to when it's 90+ degrees outside!

In my case, I replaced the blower control (resistors) which is located under the glove compartment. It is bolted to the blower motor. The resistors solved my problem. I bought it from www.AutohausAZ.com under 2004 Mercedes SLK 320. Good Luck.
his by surching the site, this could be my problem as my blower always runs and does seem to be on high!