Air blower cab fan works only occasionally.
 

I have 2007 E350. Recently the air blower cab fan stopped working. In the morning and when the weather is cool it will work fine. But when it is warm, it does not. Some times when it is working the fan sounds like it is struggling. The air is cool when the AC is on and heating works fine too when the fan does blow air.

Not sure what the issue could be? Has anyone any ideas?

It's located under the glovebox. Common for them to go out...usually preceded by a squeaking noise. Relatively inexpensive and easy to replace.

air blower
 

I am thinking about replacing the blower to start with,. But since it still works at times, I was wondering if it might be something else. I know there are cables and a resistor attached to the blower. I wonder if I need to change them
too. Thanks for the information.

Start with the blower motor regulator as it's a common failure.....

https://www.fcpeuro.com/products/mer...216451#fitment

Same problem still
 

I finally got the motor resistor and installed it. I still have the same problem. The AC will work occasionally. Is there any fuse related to this item and where would I find it? Should I go ahead and just replace the blower now too? Any other suggestions?

Now, with Mercedes-oriented scanners easy available for $150 dropping parts blindfolded is plain stupid.
Get a scanner and check what it will tell you.
The system operates with 7 or more sensors, so dropping the parts can get expensive.
How many miles anyway? MB blower brushes last usually 300k miles, but they are not lifetime item. At least not my lifetime.

A/C blower in cab only works occasionally
 

It has 128k. How will the fault scanner help
me? As there is no check engine error light that showed up? I am willing to try what ever you recommend. Any suggestion on a good scanner to get? Thanks for the advice.

Error Code
 

I did go to autozone, and have them scan for a fault. All that came back was P0012 code. Has that anything to do with the air conditioning unit? The car runs fine.

Not every fault turns on the check engine light, and the autozone free scan is next to useless, crap comes to mind, same goes for o reilly and advance auto,

Conclusion Repaired!
 

I finally fixed the problem. I just installed a new blower which is underneath the glove box. The AC now works all the time. I got the part for $140 at https://www.fcpeuro.com. I was quoted $400 just for the part with one mechanic. The blower and resister which I had installed first to see if that was the problem were easy to installed. The AC previously would only work occasionally. Glad to have the AC back full time, especially living here in California. Out of pocket $240. $140 for the blower, $100 for the resistor ( which i probably did not need).

Thanks for all the advice and recommendations. Very much appreciated .

I just did this replacement a week or so ago because during the winter, the fan was starting to stick a little at initial start-up. Yes, it is pretty easy. My buddy who just bought an E320 4Matic also did it. FCPEuro has a good price on it.

Also, that resistor/regulator turns out to be the same one as used in the S-classes (W220's). I compared the part numbers, and they're the same.