On Friday I went out to my garage and heard a sound like a fan running. Opened the car door and fan stopped, closed door and fan started. Naturally I went online to find the problem. So many people have posted every where on how to fix the problem including that you have to change the fan. Next day same thing happened.

Picked up the manual and found out it is a normal thing to happen to dry out the evaporator box. Never have a musty smell from the A/C so I guess it works. Start stop worked fine afterwards so I guess it does not drain the battery.

 

Are you sure it was the vent fan? Did you feel air out of the vents ? There is a second water pump that runs when motor is off, a vent Fan running also sounds normal .

 

Air was coming from vent. According to the manual after 1 hour the fan will start and run for up to 30 minutes. It was just strange.

 

What year , my 13 doesn’t do that and I do get mold smell , I’ve had it cleaned properly

 

What year , my 13 doesn’t do that and I do get mold smell , I’ve had it cleaned properly

 

Start stop is real BAD for the motor , you loose oil pressure !!!! And it kills the starter and battery ! Yea EPA BS

 

2013 350 4matic and I would not have ever noticed if I had not brought some trash out a little more than an hour after coming home. I drove a neighbour yesterday and she commented on how fresh my car smelled , she thought I had a special air freshener.

Start stop cars have a different starter motor rated for the usage as well as a larger battery. Car operates so smoothly on start up you don't notice it and if I save a litre of fuel every month all the better.

 

I disable ECO mode, because it's annoying.

 

Mine is 2013 also and no blowing out vents and new batteries , both ,.

 

I don’t know if there is a moisture detector in that circuit, it would make sense if it did.
But either way, there are a couple of operational steps that can be taken to keep the air conditioner circulation system free of contamination.
Always turn off the compressor, and leave the vent fan running for at least 2 minutes to allow any condensation to dry, if you are going to shut the engine off for more than 20-30 minutes.
So either get where you are going then let it idle for 2 minutes, or shut the compressor off 2 minutes before you get to your destination.

 

I think it is just time based, because my manual says it starts in 1 hour. So I think that after an hour any ice on the evaporator would have melted and most of the water will have drained away. Then the fan starts at low low speed to dry the area. Logically if you turn off the A/C before stopping the engine the car should not go through this cycle.

In all my other cars I always shut the A/C off, blocks from my home or a few kilometres on the highway. I always though taking the extra load off would also help the engine to cool down a little more as well.