Hey guys,
New to mercedes shop. I am having climate control problems. In Oct of 2001 i replaced the climate control unit. I then had the car sitting from Jan of 2002 to Aug 2004. Now the blower motor works occasionally. when it does work, it either works perfect, goes on and off as many times as you want and blows cool air in the cold setting, or it switches from hot to cool, and will not shut off unless pushing the EC button, and off button repeatedly. Most of the time you switch the system on in the EC setting, no blower motor. If you shut the car off repeatedly, and turn it back on you can usually get it to work. I have replaced the blower motor brushes with the kit from Mercedessouce.com along with the brass fuse upgrade kit. Could it be the temp sensor at the blower motor? I have read in the service manual that this could cause the blower motor to shut off. I know there is also a temp sensor on the evaporator, and also in the cabin. I have replaced the one in the cabin. I'm starting to think it is the climate control unit because of the erratic behavior, ie. not shutting off, blowing hot air even though it is in the cool setting, having air blow out the wrong vents based upon the climate control settings, etc. Even when the blower motor doesn't come on, you can here valves opening and closing in the dash. I've also replaced the monovalve that controls coolant to the heater core. I'm hoping it is not the climate control unit, because the new one has only been used for a few months. Thanks for help in advance.

Mike