I had initially gone in because my A/C blower wasn't working (it's almost 100•F). My blower motor was shot and my relay had stopped working completely and needed replaced. So I ponied up the money and had both repaired. I drove home with the A/C blowing strong and well.

Then after I got home, I got ready for an appointment I had, started the car, and the blower wasn't working again. I took it straight back to the shop and had it looked at that day. After over four hours of inspection, it turned out the relay they ordered was bad and they replaced it at no charge and all was good.

My blower worked fantastic for a couple of days... until today. It just stopped working completely. Again. Yesterday I got in my car and it wasn't working but started blowing again after about 2 minutes. Today it isn't working at all and I've spent about 3-4 hours all together driving my car, both in the city and on the highway.

If my blower is out a third time, and the parts are good, every part of the system was inspected multiple times and showed no error, what could it be!? Also, the rear blower works fine (I have a 2006 S600 and the rear has a separate blower in the console for quad-climate zone control). The dash unit (I can't recall its name) is working fine. It senses the car's temperature when it's in auto mode and tells and shows that the blower is supposed to be increasing its speed/output, but still nothing comes out. Even when the display says "max autocool" nothing happens.

Unless it's some complex electrical issue, I just don't understand what it could be, and having the mechanic look at it for a THIRD time, well I don't expect them to really have any clue as to what they should be looking for! Any ideas or similar experiences???

 

I took it in today and I feel stupid now. I didn't think about it because the blower worked after it was replaced, but it was something I should've suspected. The "mega" fuse over heated when the original blower motor was going out and so from all that heat it caused the bottom of the fuse tips to corrode thus causing loss of contact and so no power to the blower.

Note to anyone who reads this: always check the condition of the fuse before AND AFTER replacing an electronic system of any kind. It will prevent damage, prevent wasting 4 hours at the shop on them trying to find out what's wrong with it now, and prevent the anxiety that something in your electrical system has gone bad and will be hella expensive to fix. And I don't mean expensive in the normal sense, but expensive in comparison to other repair costs for whatever Mercedes you have, especially the S-Class.

 

I hope that the pros at the shop feel even more stupid - and that they didn't charge you for their stupidity...