JEDSTER

Hi,

Here's a weird and strange circumstance on my C32 AMG, that I am hoping someone here would maybe be able to help or advice.

It's winter right now here, and I drove my car out today and nothing happen, no problem at all. But on my way home the Air Conditioning would blow air for a second without the air condition switch even on and turns off by itself (like as if my car is possessed). So pretty much the air comes on for a second and off again without me even turning the air on at all. It happens a few time tonight until I parked the car in my garage.

I am wondering what could cause this ?

c32kompressor

You could have a short to ground in there behind the air conditioning module. Can you manually turn the air on from the controls?

JEDSTER

What does short to ground mean ?

Yes, I can turn on the AC manually.

c32kompressor

A short to ground is when the power wire for the specific component grounds before the switch, there fore completing the circuit and turning it on.
In your case maybe there is an exposed wire touching a ground. The vibration from driving could be making it touch something under the dash that grounds it out

c32kompressor

With the a/c manually turned on does it do the same thing?
In other words turn off? And then back on?

JEDSTER

Oh ok.
Thanks for the explanation.

Yes, it does the same even when I manually turned it on.

JEDSTER

It's really strange.

But then today when I took the car out, it didn't do it again.

It's super strange.

Knock on wood, hopefully it doesn't act weird again.
Crossing my fingers....

c32kompressor

I have a stuck air vent for the windshield defogger so I feel ya! -_-

JEDSTER

After 2 days not acting weird.... the weirdness returned tonight.
I'm taking the car to the shop tomorrow and get it fixed up.

c32kompressor

That deffinetly sounds like a short to ground.
You might get lucky and it could just be the control unit ..

JEDSTER

Is it a pretty expensive fix or no ?

c32kompressor

A short to ground repair can be anywhere from easy to extensive depending on where the short is. The control unit is a breeze to fix. Just need the part!

ChiCho55AMG

Hey All,Maybe i can resolve my AC problem as well,I Have W209,When the car is moving the AC is too cold,but when the car is in traffic,it will get warm,any idea ? The gaz level is good,i checked with the gauge,it doesnt need any gaz,maybe sound like a clutch fan ?? Thanks for any help

c32kompressor

I'm not to sure about the a/c. The op was experiencing electrical issue

ChiCho55AMG

When the car is in traffic the A/C will turn to warm and only in traffic, on highway it's very cold, if you rev above 2000 rpm in traffic the A/C will turn cold...

JEDSTER

How much does the control unit usually cost if it is the control unit that's problematic ?

Just made an appointment to go in tomorrow. They are busy today.