HMalloy086068

I have a 2006 CLK350 conv and the AC from the passenger side vents is cold and seems to be working normally but the driver side vents seem to blow air that is only slightly cooled.
Any suggestions?

Rudeney

I've seen this happen when the system is low on refrigerant. You'd expect it to affect both sides, but often the driver's side blows warm air first. Another possibility is a damper control problem. Try the ACC test/reset - with the engine running, simultaneously press and hold the RECIRC and FRONT DEFOG buttons until their indicator lights begin to flash. Release them and they should continue to flash for another 20-30 seconds. If they don't stop, then you have a problem in the system that needs proper diagnosis (likely problem with a damper servo in the duct).

kennywong1234

Hello all, I'm having the same problem here and I tried to reset the system but not succeed,

If this is the damper problem, can we easily fix it? How critical to do this?

I just refilled the refrigerant but just doesn't help the ac system

Rudeney

If the ACC test/reset procedure did not complete (i.e. the RECIRC and FRONT DEFOG lights continue to flash and don't stop) it means there is a problem in the system. You need to get codes pulled with SDS to see what the problem is.

kennywong1234

Thanks Rudeney, but I don't wanna return to dealer and I hope this is just mechanic issue and I can fix it, because I know they will charge me huge money ><

I saw someone replaced the condenser and very good feedback, as my CLK already 10 years so should I try this?

HMalloy086068

BTW Thanks Rudeney system tested okay just low on Freon.

Rudeney

Kenny, I am not a proponent of throwing parts at problems. I'd rather do a proper diagnosis and replace the right parts. If the ACC reset never finished, then that usually indicates a damper problem. Now you need to find out which one is bad. The one that most often fails is, of course, the one that is most difficult to replace - you have to pull the entire dash and duct (including heater core and A/C evaporator). Like I said, a proper diagnosis is imperative. If you don't want to pay dealer prices, and you are a good mechanic and aren't afraid of the electronics, you might consider investing in SDS. You can get a Chinese "clone" version for around $500. It's saved me that much in airbag resets alone.

betrezra

I had the same symptom on my 04clk55. I added freon and back in the game.

kennywong1234

Thx again Rudeney, but I think I get you the wrong message.. sorry

I was tried to hold the RECIRC and FRONT DEFOG buttons but I only seeing the windows going down or up,

Anyhow, I took my car and checked by the mechanic, they refilled the freon for me and if it's not cold again then we should check the damper or maybe somewhere there is leaking,

Thanks again Rudeney!!

Rudeney

Oh, I see. If the windows go up and down, you are holding down just the RECIRC button. Holding it activates "tunnel mode" which closes all the windows and switches to RECIRC mode or opens all the windows and switches RECIRC off. You have to press booth RECIRC and the FRONT DEFOG buttons. Also try just pressing the FRONT DEFOG button momentarily by itself to make sure it is working.

kennywong1234

Hello all, after all I had successfully tested my ac and it's working fine, u refilled the refreg in 2 months ago but now the air from driver side become weak again... I'm thinking is it because some refreg pipe is leaking? But the passenger side still blowing cold air lol.. Pls share your though thanks!

Rudeney

I suspect you have a leak. Slightly low refrigerant can cause warm air on the driver's side while the passenger side is cool.

kennywong1234

Yes I had the same feeling... but how I can check which pipe is leaking? is it maybe in the front engine or in the dash? Can I DIY it? Thanks Rudeney!

Rudeney

You can get a fluorescent dye to put in the system and then use an ultraviolet light and special lens glasses to look for leaks. A slow leak will need to be checked over a period of days or weeks.

kennywong1234

Oh ok,, great idea thanks!!