i have a 2022 E 53 AMG.
i've already had the A/C unit replaced.
and that was quite an ordeal to get done. it was in August.
last week when i drove home (45 miles from dealership) from my regular service appointment the air was not blowing COLD.
the A/C was in the null position.

when i text my new service advisor i got NO response.
then in my emails i received a survey so i filled it out and let them know why i wasn't happy.
a service manager called me back.

i was told that the A/C doesn't run cold in the winter. only runs in warm weather.
i've never heard something so absurd.

i have 3 other brands of cars and they all have a working A/C. year round.

has anybody else heard this?!

 

Send another email to General Manager of dealership and say your Service Manager is a total moron and stupid. He needs to be demoted to janitor

 

thank you !

 

Well, your service manager is technically correct. In the winter it's not supposed to blow cold air into the cabin. It's blowing warm air to heat the cabin, but the AC is used to remove moisture from the air. So technically the AC cools and dehumidifies the air it sucks in, and then heats it up so you are warm and cozy. Need to clarify when exactly you are expecting it to blow cold air in the winter. The air coming into the cabin will be cold while the engine is cold, but once the engine warms up, it will blow in warm and dry air, so your windows don't fog up. Are your windows fogging up? That would indicate that the AC isn't doing what it's supposed to do. AC stands for air conditioning, not air cooling. Cooling will only happen if the current cabin temperature exceeds the set temperature, otherwise it will heat instead.

 

Agree for the most part. But it really depends on where you are in the winter. Here in San Diego it can still get quite warm in January and actual cooling of the air is needed. My AC definitely puts out air cooler than ambient when needed for those warm days. My understanding is that if the ambient air is warmer than the set point on the cabin temp controls, then the AC will do its job and no warm air from the engine will be mixed back in. If the ambient temp is cooler than the set point, then the AC gets used to reduce humidity as needed when you press the defrost button and then warm air is added back in.

 

Yes, that’s essentially what I said. It cools when it needs to and heats when it needs to. It’s an automatic climate control system. Essentially like a smart thermostat at one’s house. You set a comfortable temperature and then let it do its thing. That’s why I said we need more info from OP. It’s not that the system doesn’t cool in the winter, but it obviously won’t cool if it’s 20F outside.

 

I turn the A/C on here in MN even when in stupid negative cold weather. Only used for dehumidifying the air (snow on shoes, melts, increases humidity) but i have the cabin set to max and when it gets uncomfortable turn it down to 70-72.

 

i have the defrost set in the afternoon w/ the AC still onfor the morning from afternoon previously. so when i remote start, the dehumidify will happen.
the windows don't fog up.
it's usually in the 30's in the morning when i leave and i'm well versed in cars warming up.
then in the afternoon when i get back in the car, i revert to cooling because my dog is with me.
i turn the thermostat number to 72. i very seldom use the auto button.
i was also concerned when i picked up my car the mechanic had the temp set down to "LOW".
so i had reset the temp to 72 and warm air blows out.
the temp here in Mid TN USA is usually around 40-55 or 60 for a high in the winter time.
i understand what you are trying to tell me
but why has it been working up til the day i picked it up from Service B - Both Times........

the GM sent a message back to me saying that i need to get that in and get it fixed cuz my warranty is about to run out.
that's all it said.
this is really the biggest issue i am having with this vehicle.
no cold air can make anybody cranky !
thanks yall !

 

I think a bunch of us are confused by what you're saying. If the temp is set to 72 and it's anywhere from 40-60 outside, you would expect heating, not cooling. If you crank the temp down to LOW, do you get cold air? The AUTO button doesn't affect temperature.

 

I'm not ruling out that your AC has a malfunction, but it's very hard to tell, because you are one of the people who just doesn't seem to understand how the system works and you keep manually messing with it, impacting its performance. As I said above, this is an automatic climate control system. Forget about manual AC systems from past cars where when you turned on the AC it blew cold air and you had to manually cycle it and use the temp gauge to manual mix cold and warm air in an attempt to maintain a comfortable cabin temperature.

That's not how this system works. The temperature is always automatically controlled. Stop fiddling with it. If you set it to 72, then the system will do its best to keep the cabin temperature at 72. Don't keep changing it. If you set it to LO, it will keep it as cold as the system allows. It won't cool or heat faster if you turn the temp up or down. Just leave it at the desired temperature. The Auto button controls the airflow. Leave that on Auto and also don't keep fiddling with it. There are sensors throughout the car, including a sensor that measures solar radiation and all that is factored in. You won't do a better job trying to manually optimize it. When on Auto, it will automatically regulate the fan speed and which vents to blow out the air to quickly reach the set temperature and maintain it. If you mess with the airflow and manually adjust the fan speed or where you want the air to come out, it simply won't work well. You are hamstringing the system. You rarely will even have to turn on defrost in my experience. The windows just won't fog up if you leave the system do its thing. Maybe on occasion you may have to temporary turn on defrost for a bit, but then switch it back to Auto. But for the majority of the time, leave it in Auto and set the temperature to what is comfortable and leave it alone.

FWIW, I have mine set to 72 most of the year. In the summer depending on how much heat I have stored in my body I may lower it to 70 or 68, especially if I was out playing tennis or riding my bicycle and need to cool down. At most I adjust the vents themselves. Generally, I don't like the air to be blown directly at me. I wear contact lenses, so that dries out my eyes, but if I'm hot after exercising, then I may aim the vents at me at least for a little while. My wife is the same way. She doesn't like air blown at her, so she actually closes the vent on her side, and I also keep the center vent closed. My car has three center vents, so the one dead center is pretty much always closed, but the other two are open and aimed straight down the middle, so they neither blow at me or my wife, but cool/heat the cabin. I also have ventilated seats, so if I get hot in my seat, then the seat ventilation does a better job than fiddling with the AC.

 

I have a family member who insists that turning the AC all the way to the lowest setting cools the car faster. When I explained how it works she said well your AC must not be working well because my CR-V cools way faster than this Honda Odyssey when I set it all the way to low. Trying to get her to understand the physics of volume and thermal mass was unproductive .

Here in San Diego, I don't think that I've ever had to turn my E63's climate control to defrost to have the windows clear up. But it is garage kept and the windows are usually clean inside and out.

However in the case of my wife's Odyssey, which is also garage kept, it does help to run the defroster manually on rainy days occasionally. Usually this is because a film has built up on the inside of the windshield. I think the film is caused by outgassing from the plastic dash and is fairly tough to remove. Those magic eraser scrubbers seem to do a good job of it. It was so bad on my daughter's car the last time I drove it that I practically needed to run the defogger on a Santa Ana day . But once the buildup is cleaned from the inside of the windshield then the fogging problem goes away.

 

Yeah, foggy windows is largely due to dirt on the glass that moisture can bind to, such as the film from the outgassing plastic. A 50/50 solution of water and isopropyl alcohol does an excellent job removing that. I use the same solution on the outside. I haven't used commercial glass cleaners in forever. No matter how streak free they are supposed to be, they always leave a film, whereas the alcohol removes all the grease crud on the glass and then evaporates, and what's left is just water that you can wipe up with a microfiber. Use distilled water if your tap water isn't the best. I got this tip from a detailer.

 

In essence, there are only two questions that need to be answered. If the system is used as designed and as I explained above. Setting it to a set temperature such as 72F with fan in Auto and leaving it alone, does it cool the cabin to 72 when ambient is higher than that, and heat it to 72 if ambient is lower than that. If the answers to both questions are yes, then it's working as designed and everything else is in one's head.

 

I was just explaining this to my wife about her 22 E450 4Matic over the weekend when the system wasn't functioning properly for a road trip.

What that AC button really does is dry the air. The temp you select is just that relative to the weather outside. Just as you use the AC when it's humid (spring and summer storms), not because it's hot outside.

We dropped the car at the dealer today, still under warranty. I'm convinced the compressor took a dump. Which should be unheard of in this car from MB within 4 years and 40k miles. Yet here we are. My guys have already checked it out and confirmed no Freon leak, freon is full, vacuum is good, the compressor just isn't working when being commanded. So we'll see what the dealer comes up with.

Cheers,

maw