Mercedes: ML350 A/C blower suddenly stopped working, factory warrantee, vacuum leaks

Question
All of a sudden the A/C blower of my 2007 ML350 stopped working. The lights on all the switches and controls come on but there is no air from the vents.
I already checked the main fuse for A/C control and that is ok. Any ideas on what could be wrong? Of course, the factory warrantee just ran out! Am I looking at a major expense?

Answer
V
The blower is most likely controlled by the evaporator temperature control. When entering a hot car, the blower is held off until the compressor has had time to move enough refrigerant  through the evaporator an pre-cool it before you get the air blasted in your face. No need to move hot air with the blower.

I would raise the hood to determine if the AC compressor clutch is engaging the compressor.
Place the AC unit on max fan and max cool and start the engine.
If the compressor clutch is turning the compressor shaft and the evaporator line is chilled,  then you probably have have some problem with the climate control circulation system.
If the compressor clutch is not engaged, then you probably have lost refrigerant by a leak. The system has a low pressure refrigerant switch to stop the compressor from operating because the compressor lubricant circulates along with the refrigerant. Operating the compressor dry or under very low pressure could become a very expensive compressor replacement job.
I would locate an independent AC service and have them check the system. If you in fact have a leak that will by law need to be repaired before re-charging. The service center will hook up a refrigerant recover unit and remove the freon they will place a vacuum on the system to make sure it will hold without leaking down. If the vacuum leaks away, then they will have a refrigerant sniffer and or a dye that can be place in the system and viewed with ultraviolet lite to help locate the leak.
If the fitting 'o' rings are leaking then the repair should not be too expensive. If you have a bad compressor or leak in the evaporator that can be a very pricey fix.
Good luck and let me know what you discover.
Rob