Vcappello44

I have a 2007 Mercedes S550 and live in south Florida. In the morning my a/c fan blower kicks on and blows ice cold air. In afternoon when I go home from work it doesn’t kick on. So I’ve been reading threads and replaced fan motor and resistor and still same issue. Climate control buttons work. AC is on but no fan blowing air. I tested fuse and is good when OBD scan is on shows 0v to fan with AC on. Does anyone have any ideas. Was wondering if maybe a bad wire out of fuse box to fan blower. I don’t want to buy new control module and it still doesn’t fix my problem.

BOTUS

the symptoms you have don't sound real - r u saying 100% no fan no matter what you do with the controls ? but in the morning its all normal again ?

modern cars and especially the w221 basically can't be worked on without dealer spec diagnostic capability - the system is extremely complex, and decent diagnostic will tell you incredible amounts of information to help you try and find out what is playing up

a duff fan from water ingress is quite normal on a Mercedes - if you wish to fight your way to diagnostics - you might still be at it next year - but you could take out the front battery and take a look at how much detritus is under the removable battery tray (unbolt it) - give that a good clean along with the silly plastic screen drains near the bonnet hinges - if it was horrific - pull up the front foot well carpet and look for furry modules in and around the passenger side

NOTE: the rear battery will have power around the cabling beside the front battery (so best disconnect both before playing)