W211 Air con, always on even when light is off?

[postmastergeneral]

Good afternoon ladies and gentlemen

Hope everyone is having a wonderful sunday afternoon

A quick question please, when I turn the fan on and the temp selector is on the blue setting or just above, the air coming is rather quite cool. however, the A/C light is off but the cool air really feels like the air conditioning is on.

so does the air con stay on even though the light is off, or can mercedes miraculously cool air? this was happening at the peak of summer too

Many thanks

G

 

[television]

When the EC lamp is lit, the air con is off. If you have an auto setting,,I would just use that and leave the controls set to the desired temp.

Yes the sun is shining, a wonderful day

 

[postmastergeneral]

Hi Malcolm!

i would leave it on auto but i really dont want the aircon to be on as im trying to save energy (yep im a tight git!)

i have never seen an EC lamp? where would that be?i just see the little light that is actually on the A/C switch

thanksmalcolm

G

 

[television]

OK the EC lamp may not be there on the newer cars, But all you save is the difference in temp from the outside to the inside. When doing my fuel economy test last week,,I could not detect any difference in the consumption with it off or on,, the joy have having windows that do not mist up with it on,,out weighs all else in my opinion

 

[postmastergeneral]

yeah you're right Malcolm, I will do that from now on. Many thanks as always

G

 

[Alex Crow]

the aircon on these w211 cars does actually stay on, even when the ac-off is selected. hard to believe i know, but true. the ac will run at something like 30% duty cycle at the pump bypass/recirculating valve, i do not know how long it does this though.

i know this because we had a w211 in last week with an odd noise behind the dash. pressing ac-off did nothing, turning off the climate control panel with the '0' switch made the noise go completely. this was entirely repeatable. on star i could see that the pump was running at 30% with the ac off selected. as the customer was unwilling to change the pump immediately (to stop the noise, and no, it was not just the "whooshing" noise from the expansion valve) i changed the coding in the acc module to ac-off straight away at button press. hey presto the noise now stops immediately the ac-off is pressed! every day is a day at school. yes, the customer knows that immediate pump replacement is recommended.

 

[postmastergeneral]

lovely thanks for that!just what i wanted to know! so i need someone with a star machine can do that? can this star machine also take the safety feature off for the dvd screen while driving?

thanks so much guys, car is on auto now anyway until i can get it disabled

G

 

[Daeths]

pm me your email address and i can forward you instructions to enable DVD/TV in motion via comand by accessing hidden features.

It is illegal and not recommended - just to cover my backside :lol:

 

[xavierx]

Hello

Firstly : With any reasonable sized engine, you would not notice a difference in economy with the AC on or off.

Secondly : Completly switcing off the AC is not a good idea. There is a very good reason why the pump continues to operate even when you set it to off..... This is because air condition systems need regular use to keep them both lubricated and clean. You will find that any car with climate control these days will have always on AC

HTH

 

[Alex Crow]

hello xavierx, the pump on these models does run constantly. the control comes from a bypass valve arrangement built into the rear of the pump housing. this design avoids the on/off clutch arrangement that can fai,l and puts high inertial loads on the pump mechanism. if it were bad to have the ac off then star would not facilitate the coding of this option.

i suggest the reason why it runs on for some time at 30% is to avoid the sudden moist air dump that accompanies a sudden cut off of ac after it has been used hard then turned off. i understand the ac off button DOES turn the ac off in standard uk coding, but not immediately.