legatolimo

When you guys turn on AC is your red indicator light ON or OFF? For some reason when my AC is running the red light is OFF, and when I turn AC OFF the red light is ON.

I'm confused. Usually when you activate something a light is indicating ON. Right? I do have one code error, which I already traced. The sensor in the overhead console is broken, but even when it was good the AC control was still the same way.

How is your AC?

wallyp

The button is labeled AC OFF, and the light shows when the function is activated - that is, when you have turned the AC off. The Mercedes Benz engineers consider the default condition to be AC on, so they warn you when the AC is off.


The AC is designed to be unobtrusive, so you never notice whether it is off or on. You almost never get a blast of frigid air - it just makes you comfortable.


The sensor and tiny fan in the overhead console are important to the function of the system.

legatolimo

Okay. Yeah I saw the button being labeled with OFF, but was slightly confused because in my mom's E350 the AC button light is OFF when OFF and ON when AC is running. Oh well. At least I'm not dreaming. Thanks for the explanation and confirmation.

As far as the overhead console goes. I will be replacing it shortly. For now I just have the AC set to Low on both sides.

legatolimo

Another quick question for you. What really does the Auto function mean on this AC? I just never seemed to use it as I simply just have the temperature always adjusted to very cold and fan speed on low.

Welwynnick

It adjusts the fan speed automatically. The speed generally goes high only when there's a big difference between the set temp and the actual internal temp.

Nick

legatolimo

I see thanks. So it's simply a function, which you can utilize, but not really much of a use if I just want the AC to be set to the lowest temperature at all times right?

wallyp

If the system is working with anywhere normal effectiveness, the car should become uncomfortably cold after a short time.


The system is very complex, with compensation for direction and amount of sun, auto temp control, fan control, and air flow thru each of the many outlets.

legatolimo

Well, uncomfortable to most perhaps, but I have a medical condition. I have extremely high tolerance to cold, and wish I could bring the AC down to 30 if possible. Lol.

But I will replace that sensor in few weeks. Thanks for all the information.

lganski

legatolimo - You should consider moving, (or vacationing) to the Northern Midwest, or New England, that would cure your tolerance for cold. LOL

legatolimo

Lol. You are absolutely right. I will consider that.

trombone

before you by a new sensor you may want to clean the one you have.
On an around the small fan lots fine dirt, dust, fleece settles, including on the sensor.

legatolimo

I actually already had the console apart, and discovered the thermistor connectors are broken. The only way is to get a new thermistor and modify the way it is installed or purchase a replacement console. I found a Console on eBay from a 2006, so I'm hoping the sensor there is still good. New console is $485 at a wholesale price.

wallyp

Quite a few of us have discovered the same problem, and repaired it by just soldering the connections back together. I had to add a couple of inches of fine wire to make it easier. It is a delicate operation, but very doable. If you don't think that you can do it, you might want to see if you have a friend who can help you with it. Free is good...

legatolimo

Oh I can do it. It's just easier to replace and plus I would really like it to be original.

And forgot to mention my thermistor broke in a very bad spot. close to the end, so it will be little difficult soldering it.