Ml270cdi - dodgy climate control/air con

[bruno27]

Greetings one and all, i have recently bought my first mercedes in the form of a 51 plate ml270cdi(facelift) 65,000 with full service history, some mb some not. Whilst i am very happy with the car i am becoming increasingly frustrated with the climate control/air con. When i bought it i checked everything over, particularly that all switches/electronics worked etc. And thought the c.c was working fine, but after a few days noticed that it was regularly blowing very warm but put it down to my own stupidity or not reading the handbook properly (homer's 'iliad' is an easier read!) i eventually had it re gassed (no gas recovered but no apparent leaks, assumed gas lost during previous maintainance maybe) it still runs either warm or hot, with no apparent control from the temp dial. If i set switch to minimum, turn off ignition and wait a few minutes, turn ignition back on the temp will be cooler until i move the temp gauge then its back to warm or hot only. I also noticed it always blows up on the screen even if set to footwell.
I'm used to a/c but not climate control am i being thick here or has mercedes wizardry had a wobble.
Any knowledge of an independent mb mechanic in the north wales area would also be beneficial and welcomed!

 

[lynall]

Climate control is basically just air con with all the flaps controlled by small electric motors.

Describe the cc unit as on the W210 you can do self diagnostics and see all the temps etc on the screen, just not sure what type ml has.

Have a look here might help http://www.eclassbenz.com/node/27

Also here http://www.bba-reman.com/content.aspx?content=mercedes_climate_control



Lynall

 

[bruno27]

Lynall, thanks for your views and the links, unfortunately my ML has 3 manual dials (1 for temp, 1 for direction & 1 for fan speed) but no display.

bruno27

 

[npuk]

You dont have climate control then, just standard AC. Guess the first thing to do is take the AC switch panel off and check the connections on the back

 

[Mercedes cozy]

just a quick check. is the red light on or off when you are testing the ac

Its also worth having your fault codes read by a star machice and that may reveal the problem.

 

[lynall]

Is the air con defo working? mine packed up recently and was the wire to the compressor broken at the little plug.



Lynall

 

[lynall]

Assuming ive got the right pic it looks like its nice and simple just 3 cables, could be just one has come adrift so even though you can turn the knob the cable is not moving or only partially moving.
Just found some more pics here http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=163174%5F06H&M=113%2E981&GA=722%2E666&CT=F&cat=06H&SID=83&SGR=045&SGN=01 item 95, 104 and 110

Lynall

 

[bruno27]

the red light off.

 

[npuk]

The AC is on when the red light is on.

 

[lynall]

The AC is on when the red light is on.

On the Ml yes but most of the older range 210/203 is the opposite way around reverting to same as Ml for the later cars.



Lynall