Hello everyone, once again I'm back for your support..This time I purchased a used 2007 GL450, and aside its normal pains and aches (oil leak from seals on the back of the engine, remote control stop working, etc) I have an issue now with the HVAC, which seems to be the 3 zone one.


This is the story..


The SUV a/c had been working great until we decided to take my other car (e55) for vacation...?? Yeap, it got jealous perhaps, but when we came back, the a/c was not working just from sitting on the driveway.


I have to mention that everything seemed ok when it comes to running the ac, and I mean, all vents change when adjusted from the control module, rear controls, etc. It just does not blow cold air nowhere.


Needless to say this compressor does not have the visual help of having a clutch in the front of it, it seems to be spinning all the time. Which by the way, is exactly what I have on the e55.


I learned somewhere on the internet, that this are variable compressors and are suppose to be control by a valve if I recall properly.


I took the SUV to a friend that has an AC machine , to make sure I had some Freon. I learned that it did not. so we went ahead and vacuumed the system and added the right amount of Freon. That did not help.


I also read somewhere that the system needs to be reset, when you run out of Freon.


Well, I need some advise on how to troubleshot this problem. I have been a mb owner of at least 7 different models, and have never allowed any dealer to work on them.


Perhaps You guys can help and advise me if there is a way to read the codes from the control module like I used to from my c and e class vehicles. Or at least reset the system.


I found this link on the web, but my control is just a bit different, and the instructions do not seem to work with my model.


http://www.ehow.com/how_7899592_rese...ac-system.html


Please HELP...it is real hot here in Texas!

 

Sounds identical to my problem, did you get any answers?

 

I had the same issue. System was purged and refilled about a year ago and it worked fine, but at the beginning of the summer the system started to fail again. After running for two hours it frozen, so I had to turn off until got defrosted. No leaks, at the end I got the compressor replaced. I think that after 13 years and more than 214K running, the reliability of the compressor is good, considering that it never got new Freon and oil.

 

Had to replaced the compressor, apparently, an oil leak was dropping all over it. And somehow messed it up.