elijahwww

I have one annoyance that is probably correctable via the settings, so hoping someone knows right off hand. Sometimes when I come back into garage I notice my '12 GL450 is running the ac/heater fans. Through the glass I can see the "Auto" light is turned on. As soon as I open the door it goes quiet and the light goes off. How do I disable this? I don't lock the car in garage. I power it off with a single Start button press. Is there some other sequence to power everything off or a setting to not cool/heat the car when it's parked? Currently it runs those fans for longer than an hour. That cant't be right.

Another strange thing, the car will make a single whooshing sound when I open any door after car's been parked for a day. Is that some kind of airbag prep sequence?

alx

If your recirc button is not pressed your hvac module in the front fan housing is on its way out.

Happens most often when air is very humid.

It essentially shorts out when wet and stops when dries out. Eventually front fan quits altogether.

The whooshing sound is excess air being released by the airmatic. This is normal.

PeterUbers

All things my 2014 e63 does and likely normal ... These Benz cars make lots of sounds while "off"

BrianD

2010 gl550 here and makes the same whoosh sound when doors r open after it's been parked. Also I've seen my fan on the exact same way you describe. I have no idea why its in sometimes. There is a "rest" mode but you generally have to turn it on for it to blow after the car had been shut off

LukkyStrike

The ac fan being on is a feature. Check your manual. Pg 135 mentioned this feature. It will run for a while to keep the cabin warmer while the radiator is still hot or your battery is above a voltagr set point. It will also run it to dehumidify the cabin in muggy situations.


The air valve sounds are the truck settling once everyone has left the vehicle. It will try to level out. This is normal.

zspeed10

The "Rest Feature", which is used to keep the vehicle comfortable after being turned off by blowing hot or cold air (until the evaporator is warm or the heater core is cold), is similar to the process used to remove condensation from the evaporator after the ignition is off. The blower motor runs to dry condensation off of the evaporator to inhibit mold and mildew growth which can cause foul odors. This will happen at times even when outside temperatures are cold because the car will use the A/C to dehumidify the air inside to keep from fogging the inside of the windows. If it were a malfunction of the blower motor regulator (not "HVAC module") as previously suggested, the LED on the A/C control panel would not be lit and it would likely run until the battery died, at least once.
So,that is normal.
It may or may not be able to be changed with a licensed SDS by a dealer, I would highly recommend that you leave it be. Nobody wants stinky socks smell when you start the car.
The whooshing sound, normal as well, is pressure relief from the reservoir. It will hold higher pressure to react quickly while driving. When at rest (signaled by a door closing) it will expel air to relieve the pressure on the valve assembly. Sometimes there will be enough pressure in the reservoir that it will "blow off" more than once.

alx

a blower motor regulator is a series of resistors also known as "final stage".

however, in this case the cpu/memory/buffers layout on the circuit board and CAN addressability make it an integral part of the hvac system. remove the fan and address hvac module with sds - you will see "failure to communicate".

when a recirc/dry of the evap core is initiated the ac/ rest led on the climate dash will light up.

the op stated that the "auto" button is lit up which is _not_ the ac/rest light.

any "mystery" uncalled for blower operation without the ac/ rest button lit is an indication of fan hvac module being wet and generally on its way out. they die a lot and they all do it the same way. just different leds are lit (except the proper ac/rest one) lol...

Daniel123

I have 20150 GL450 and the heater blower stop blowing air out every thing else looks like its on and working but no air coming out? can it be a fuse and were can I located it