Air Con mystery

[sean sherry]

Do we have a Gurue on Air Con in our midst ?? My Climate Air in the C 250 2011 year works well when it works .... If the temperature is in the mid thirties with the car left in the Sun the air Con blows hot Air for 5 to 10 minutes before the compressor kicks in. There should be an interior Sensor somewhere but I can't find it via the Net. Lots of stories in the Net about the same type of problem but no definitive answers. Lots of ads from workshops in Sydney who say they are experts in Air Con in European cars. But I cannot find an exclusive Air Con specialist experienced in Mercedes Climate Air ?????

 

[WGB]

Have you asked an MB Dealer or a major M-B Service Centre to run the diagnostics on it.
Might be worth the money to start with a definite answer if it can be obtained.

Bill

 

[sean sherry]

Fortunately I have a local Guy who has a very professional Scanner. Many posts on the net have not shown any magic bullets to sort this issue. All the comments about Dealer fixes are negative. I may have found a way round the issue... Setting the system to Max Cool.... then there is a Blue button, which I'm guessing is Defrost ( ?) This together with Auto Air seemed to work even at only Engine idle. Ie low compressor speed. The next 35 plus degree Day will be the acid test .

 

[BenzBoy]

You really do need a proper diagnosis to ensure continued delivery of cold air. If you don't want to go down the route of a dealer then why not drop the car down to Paradise and get their tech to look at it? He did the Spirit, the Phantom and the GTi6 with excellent results each time.
I can recall the days before aircon in cars and it's not a pleasant memory....
Regards,
Brian

 

[Patrick_R]

Brian,

Very mixed memories we have.

As your dad was an avid Holden man, you would have experienced all the ups and downs of pre air conditioned cars as I have.

Swimming in sweat in the back seat of my dad’s FC, EH and HD are memories one can’t forget.

Recent drives in my FB Special, brought those memories straight back.

Mixed memories for sure, great memories as a kid doing things with the family, and bad memories of sweating your back side off to travel to cool down at the beach or river, to then sweat profusely again on the way home, plus the added horror of being burnt bright red (no sun block back then) just added more pain.

Yes we do remember those days very well.

So Sean,
Get your car to Paradise STAT and get your issue sorted now, for yours and your families sake

 

[sean sherry]

To day in 39% the Air Con is behaving !!! After I set it ??? by turning it to Max .. the Blue Dot.....and holding down Re circulate . The Auto setting now also works... ie with the temp set at 22% the fan cycles up and down as necessary. Time will tell .

 

[Styria]

Brian,

Very mixed memories we have.

As your dad was an avid Holden man, you would have experienced all the ups and downs of pre air conditioned cars as I have.

Swimming in sweat in the back seat of my dad’s FC, EH and HD are memories one can’t forget.

Recent drives in my FB Special, brought those memories straight back.

Mixed memories for sure, great memories as a kid doing things with the family, and bad memories of sweating your back side off to travel to cool down at the beach or river, to then sweat profusely again on the way home, plus the added horror of being burnt bright red (no sun block back then) just added more pain.

Yes we do remember those days very well.

So Sean,
Get your car to Paradise STAT and get your issue sorted now, for yours and your families sake

Hi Patrick, that's the good old Australia as I knew it and also hated, but today think back fondly of what Australia was like and still should be today. One must recognize that the "Good Old Times" weren't always that good, but we always coped - probably because we knew nothing better ! In those days, the late '60s and '70s I drove Rovers and I always found them reasonably comfortable even on very hot days. As I said, we didn't know better. Regards Styria

 

[Patrick_R]

You are absolutely right Styria, not all the old times were necessarily good

But great memories for sure. It’s always great to think back where we have been, and it is so interesting to see technology as it appears and what will be our kids and grand kids “good old days” memories.

Due to our vast open spaces, and distances between friends, family & places of interest, the car will always be part of those memories for everyone, past present & future.

 

[Patrick_R]

Please see new thread re memories so not to cloud Sean’s Issue here.

 

[sean sherry]

I now read on the Net, that if the Battery has been disconnected the Climate Air Con has to be reset with a Scan Tool. I disconnect the Battery occasionally to reset the ECU and TCU. But it always been ok on other occasions ???
I also learn that these Climate Control Systems are very complicated and require profession Tools and knowledge to sort out.
This morning it was at least 10 minutes before I got any cold air, but twice, later today, I got very cold air within 30 seconds ????
I also learned that there is no Compressor Clutch, but a "variable Swash Plate " constantly driven !!

 

[sean sherry]

No faults flagged ! Working today with cooler Temperatures. My local guys says that after the Battery had been disconnected it takes time for the body module Computer to reset itself. Again time will tell...... on the next hot Day, upper thirties ?

 

[WGB]

I assume the C250- has a small auxillary battery like most recent M-B's which is specifically to give a stable voltage to various electronic systems.
They seem to fail every two to three years but the car keeps running without them.
Does your C250 have such a battery and is it in good nick?
Bill Babe

 

[sean sherry]

I can't find an reference to an Auxiliary Battery in my W204 2011 year model.
Some Posts suggest that a warning light should appear if an Auxiliary Battery is faulty. I'll check with the local dealer when they reopen

 

[sean sherry]

Learning to live with it !!
Amongst the many Posts on the net with the same issue , I have adopted the one who say he has learned to Live with it. Five or so minutes after initial start up is no hardship when all is well for all stars during the rest of the Day. I also noticed reports that the Nippondenso Air is much colder than the Mercedes Systems. But even in the very high Thirites yesterday in Sydney, the cooling was quite acceptable all day.

 

[c107]

My wife's E350 does this also. Maybe not for 5-10 mins, but sometimes for 3-5 mins.

I don't recall if it always did as I don't drive the car all that regularly.

 

[Michel]

Maybe earlier cars don’t suffer from that problem?

My 2000 CLK430 get freezing cold air out of the outlets in les than one minute!

 

[BenzBoy]

Most modern climate control systems will not blow air into the cabin when first started. Instead, they will circulate the air within the system until it achieves the desired temperature before opening the vent into the cabin. Could this be part of your issue Sean?
The ML is a manual system and just blows air at whatever temperature until it cools (as Michel reports; in less than a minute). All my aircon systems run at about 7 C output at the main vent. Have you checked the temperature of the air at output Sean?
Regards,
Brian

 

[sean sherry]

Yes Michel and Brian are both right..... being too clever by half can breed it's own problems. It seems that the Compressor is not doing its job for 5/10 minutes. There is a Compressor Control Valve which may be the culprit , It is electronic so it could also be a power supply problem which comes from the front SAM unit via a control somewhere.

 

[sean sherry]

Still a mystery... this morning with temp. at 22% the air Con came on after about 20 seconds. ..... On when I don't need it !!!

 

[abl567]

It's removing humidity.