W169 A-Class Air Conditioning

[shaungjones]

I have a 6 year old A-Class MkII 160CDI. I don't think the air con is working. The red light illuminates but I don't hear any evidence of a compressor coming to life. Certainly no chilly air but I wonder if it is more than just a re-gas. Do compressors fail on this model - or is a blown fuse or belt problem a possibility ?

Thanks in advance for any suggestions.

 

[ctech]

i had a 56 plate A class until recently and i had it regassed at kwikfit after a few months it wasn't as good as it should of been,originally the guy in there thought i had a leak since the machine was rattling for quite a while but after a few minutes the machine had created a vacuum quietened down and the regassing started, i think you have to suck it and see if it does leak you can get it regassed with a uv dye / colouring in it so leaks can be traced easily.

 

[shaungjones]

Hmm, does the compressor stop if there has been a gas leakage ? I am just a bit puzzled that I don't hear any change after pressing the A/C button, my memory seems to tell me I should hear the compressor start up - right now I hear nothing. I am trying to find out if there are other common faults with A/C failing as well as gas leakage.

 

[stewartw]

The compressor will not turn on if there is no pressure in the system, this is for safety reasons, there is a pressure sensor switch which will deactivate the compressor to prolong the life of it, so it's not running on empty so to speak. Its located on the reciever/dryer.

here is i pic of the sensor

I had the same problem, I had the system re-gassed at ATS, and 5 months later had no cold air, you can see from the pic below where it has leaked from the condensor. The dark patch to the right & also behind the intercooler once removed.

Eventually I replaced the condensor myself and had it serviced and pressure tested by an air con speciallist. All is working so far will keep all updated on other post to see how long this will last.

below is the link to remove the front bumper. It took me about 50 mins to remove, that was my 1st effort, doesn't even take me 10 mins now, it takes longer to make the car safe and get all the tools ready really.

http://forums.mercedesclub.org.uk/showthread.php?t=96126&highlight=w245

Here is the link for the condensor replacement, W169 would be similar.

http://forums.mercedesclub.org.uk/showthread.php?t=98596&highlight=w245

Hope this helps.

 

[Wingnuts]

Cant help, but I thought it might be timely for anyone new to the 2005 onwards W169 that Red light ON is actually AC OFF on some models eg my A150. Took some confusing time for me to find that out.
Not sure when they changed it possibly 2006? but the handbook does not explain it well at all.

 

[shaungjones]

So far so good.

Thought I would report in after my A160CDI visited the garage today.

There was no sign of gas in the system. It was prepped and re-gassed and checked for any leaks. All done - £45. The car is 06 plate and done 72k so perhaps a re-gas was overdue.

Thanks for all contributions.

PS. for information the ROS disc brake was replaced as the one removed was warped and causes severe judder when the brakes were applied. Also I have a faulty glow plug and been told it is very labour intensive (about 5 hours) to renew. Gulp.

 

[realitybites]

Thought I would report in after my A160CDI visited the garage today.

There was no sign of gas in the system. It was prepped and re-gassed and checked for any leaks. All done - £45. The car is 06 plate and done 72k so perhaps a re-gas was overdue.

Thanks for all contributions.

PS. for information the ROS disc brake was replaced as the one removed was warped and causes severe judder when the brakes were applied. Also I have a faulty glow plug and been told it is very labour intensive (about 5 hours) to renew. Gulp.

This info has saved me a grand today. Tried to px my a class in and dealer said compressor was faulty so tried to knock a £1000 off of a possible buy so thank you.

 

[realitybites]

Any recommendations to get my aircon recharged. Am towards Uxbridge UB5.
Thanks

 

[snail]

Cant help, but I thought it might be timely for anyone new to the 2005 onwards W169 that Red light ON is actually AC OFF on some models eg my A150. Took some confusing time for me to find that out.
Not sure when they changed it possibly 2006? but the handbook does not explain it well at all.

I think they changed it in the refresh in 2009. The old 168 A-Class also had the red light = OFF; our 2010 A170 definitely has red light = ON.

Just looked at the interactive manual and it seems pretty clear now:

Activating/deactivating
To activate: press the A/C button.
The indicator lamp in the A/C button lights up.

To switch off: press the A/C button.
The indicator lamp in the A/C button goes out.

It also mentions a fault code of three flashes if the cooling is not functioning.

 

[realitybites]

Had my aircon regassed. No gas in system at all. It all seems colder but I can see no rise or fall of revs as it is turned on and off. Seems to be cold both on and off as well. Garage said there were no leaks as well.