dadiz

Is it normal to have blower fan turning on and running sometime after shutting off car? I have a 2012 ML350 Bluetec. I started noticing this on occasions last summer. It typically happens on hot and humid days. Just yesterday, I noticed it running again and just happened to time it. The blower fan came on at around 10 mins after shutting off the car and ran for about 20 mins. Some googling suggests this might be the afterblow feature that drys the evaporator? There doesn't appear to be any information on this in the manual. This is not the AC rest which is in the manual. I never use it.

Anyone else experienced this?

Plutoe

I would have you car looked at by someone who has the diagnostics--there is an issue with the fan module.

dadiz

This happened last summer on hot and humid days. I had a Xentry diagnostic done a few month ago. Everything came back ok.

When this happens, all the factors I have noticed seem to be very consistent.
ie.
- blower fan comes on 5-15 minutes after shut off and then runs for 20-25 mins
- seems to be dependent on Garage temperature. Only happens when it's really hot & humid.
- The blower fan on passenger side runs at a very low speed. AC is NOT on. Only blower fan is running.
- Dashboard lights are all off.
- Fan turns off after opening door. Fan turns on again when closing the door. Fan will eventually turn off at around 20-25 min mark.

350MH83

I believe this is on purpose to reduce the mold smell that is very common in Mercedes. I know there was a service bulletin about it, where they had to reprogram the AC module. I guess yours has been reprogrammed at some point during general maintenance.