Cone1

I have an issue with the AC on my 2011 E350. Sometimes when I switch the AC ON during driving, the red light comes ON but it is not cooling, but if I restart the engine, the AC starts cooling perfectly almost immediately. Another issue is that I want to switch the AC OFF during driving and AC button is not working, it stays with red light. Sometimes after next 5 minutes it starts working again.
Does anyone have the idea what the problem is?

thefisch

Let me ask, how does the climate system perform when you leave in on auto? Does the AC blow cold when your press max AC? Just wanting to make sure it runs as it should while in auto mode and max AC.

You may want to inspect the compressor clutch operation while someone sits in the car and cycles the AC button on/off. Let us know what you see.

Cone1

ok, I went to try it. The car is in garage, the engine is hot from previous driving. I started the engine with AC OFF and it happened again, when I press AC to start cooling, the red light came up but no cooling at all within next 2-3 minutes. Then I tried to repeat to press AC ON and OFF and ON and ZONE button as well (just for try). After one more minute the big fan in the engine started to work and the AC started cooling. Your question about the MAX COOL, If I press MAX COOL during cooling , it just set max fan of the air flow, it works normally I think.

thefisch

If MAX AC blows cold then you're probably fine. I would also run the car on auto for your next few trips to be sure it can maintain the desired temp.

These modern climate systems are smarter than the buttons on the controls lead us to believe. The system is taking many parameters into account like outside temp, humidity, etc. FWIW I leave mine on auto and just lower the fan speed if it's blowing too hard.

KEY08

But you know as soon as you touch that fan button it is no longer on AUTO.

thefisch

Yup, the light goes out and I just hit auto again if needed.

KEY08

bachree

I had the same thing happen to me twice in three years on my 2010 E350. Will be watching this. The last time it happened it lasted 45 minutes when i was in heavy traffic and all of a sudden started working when i pushed the car a little to 2500 RPM. Car was running at less than 2500 RPM in heavy traffic when AC was not responding.