[:-] the outside air vent system is stuck in closed position. Will not let outside air in at any fan speed or vent setting. Any suggestions?
Also have issue with auto door locks not locking anymore when speed reaches 10 mph. Otherwise they work normally manually.
Any suggestions where to start?

 

Well have you already checked your Mecedes Benz AC condenser?The AC condenser is one part of the air conditioning system that needs constant checking, especially if you notice that the temperature in your auto interior seems to be abnormal....I hope I can help.

 

if your car has a pse pump, then that may be faulty. Mercedes loves to use vacuum to control things like a/c flaps and door locks because they're quiet. I don't know if that year uses a pse pump, but if it is bad be ready to put up with it or shell out some serious money, i think just the pump is $900.