androdev

My 2012 W221 car has the option 582 AIR CONDITIONER IN THE REAR. I have started getting foul smell in the rear due to mold, etc. The front cabin doesn't have any issues. The smell can be felt only in the rear. I sent the car to the dealer and they did their MB Contracept, etc. treatment but I suspect they did that only to the front HVAC because things haven't improved much in the rear.

Does my car (with 582 option) come with a separate heater/evaporator coil under the arm-rest behind the rear AC vents?

If yes, how does this evaporator drain?

I am planning to spray "1Z Einszett Klima-Cleaner" to get rid of the mold, etc. but I am not sure if it can be used for the rear HVAC. I found a good document for W220 (http://www.mercedestechstore.com/pdf...2010-30-02.pdf), but couldn't get much info on W221.

Thanks in advance.

konigstiger

Note rear systems (582) only draw in interior air. Here is a diagram of system:

10 evaporator housing
20 temp sensor (x3)
40 actuator motor (x2)
50 blower regulator
60 blower motor
90 grommet condensed water drain
150 evaporator
160 heat exchanger

androdev

Thanks konigstiger. Good to know that there is a drain for condensed water at the rear as well. But it looks like the heater core will block access to evaporator core if I try to use one of those AC cleaners with long spray hose.

E300_Diesel

Thanks for the diagram! Now I know I'm not completely crazy when I convinced myself that I get better fuel economy with the rear A/C turned off...Is there only one compressor though? Does having rear A/C on just put addtional load on the single compressor or is there a second electric unit like on some mini vans?

konigstiger

1 compressor

E300_Diesel

Thanks!

ChesapeakeLimo

Never ceases to amaze me the amount of collective knowledge and resources the membership has.

I have a 2010 S550 with the 4-zone climate (rear A/C). I recently replaced the rear blower motor and had the A/C compressor (and drier) replaced. Now I have the fan blowing in the rear. However, with the rear on the lowest setting (LO) I do not have air conditioned bold air blowing. I can adjust the setting up to (HI) and the heat turns on, and back down to (LO) and the heat is off but the air is not cold like the front registers. I have to believe that there is some kind of switch or valve which controls refrigerant to the rear evaporator? Can anyone give me more information or where I need to look to diagnose/repair this problem?

motomerc

The following post might help you (it's for w220 but I am guessing applicable to w221 as well):

http://www.benzworld.org/forums/w220...ml#post5828823

Also take a look at this Chinese site if want to appreciate the complexity of your A/C :-)
http://www.vw8848.net/view_w0h3zrxg2rdubed4.html

ChesapeakeLimo

I have to wonder about the how the rear A/C system is designed to function? The 'duo-valve controls flow of hot coolant to the rear heater core to provide rear compartment heat, so shouldn't there be some kind of device controlling flow of refrigerant to the rear evaporator core? I removed the center console and replaced the rear blower fan assembly noting it blows air through the rear evaporator and then through the rear heater core then exits through the rear flaps to the rear air registers. So logic says that when the rear A/C is set to 'LO' that the flow of refrigerant is switched on? Since everything is functional other than refrigeration to the rear evaporator, the question begs where is the circuit that controls this switching functionality? There HAS to be some electronic switch that the rear climate control energizes to set this refrigerant flow. So, WHERE is this switch/valve and WHAT circuit/fuse/etc. controls it?

motomerc

Could you tell me how to open central console to have access to blower, evaporator, etc.? I am sort of a beginner, so some step-by-step instructions would help.