ML320 Heater won't work?
A/C is freexing in engine bay upto firewall, but i havent got any control over it inside the cabin, if Iturn temp dial to minimum (blue) it still blows warm air, Whilst I cant hear a clicking from the blended air motor, there is noise from a flap beneath the windscreen vent. it cycles but sounds very tight and laboured, I also have the urge to check the blended air motor and linkage. my ML is a R/H drive model, all the posted fixes seem to be for L/H drive variants so will the motor be on MY drivers side or passenger side of the dash. Ive had the radio and centre section out, couldnt see it, had the instrument cluster out today, still couldnt see it, any help/suggestions would,be appreciated.
www.PlatoTeam.com - Arizona Realtor

Well, there a NTC resistor (sensor) behind this grille below the low range switch senses the in-cabin temperature. A white hose (about 5/8" diameter) connects it to the main climate box thus drawing air across the sensor. This sensor is directly behind this grille (if you look carefully thru the grille in this picture, you can sor-of make it out) Anyway, the air temperature is controlled by a variable resistor rotary control. Signals from the resistor to the amplifier determine the desired interior temperature output of the system. A switch at detent position at the full counter clockwise (maximum cooling) position overrides the air recirculation switch to close the fresh air door for maximum interior cooling (with A/C on). I'm not kidding, by dumb luck, all I did was to push the hose back on and my Blend Air started working as advertised!!
To access this hose, follow the instructions for pulling the radio in this thread. Once the radio is out, it is easy to push the hose back in place behind the sensor.
BTW, hats off to all posters on this site...you guys/gals have saved me a butt-ton of $$$!

A/C is freexing in engine bay upto firewall, but i havent got any control over it inside the cabin, if Iturn temp dial to minimum (blue) it still blows warm air, Whilst I cant hear a clicking from the blended air motor, there is noise from a flap beneath the windscreen vent. it cycles but sounds very tight and laboured, I also have the urge to check the blended air motor and linkage. my ML is a R/H drive model, all the posted fixes seem to be for L/H drive variants so will the motor be on MY drivers side or passenger side of the dash. Ive had the radio and centre section out, couldnt see it, had the instrument cluster out today, still couldnt see it, any help/suggestions would,be appreciated.
Did you get any infor regarding where the air/blend motor is positioned on the RHS ML320? I also have a Right hand side model and need to replace my air/blend motor.
Appreciate any help that you can give.
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Brian you are on the wrong forum. Here are the instructions for removing and installing the Blend Door Actuator, but in the future you must direct all further questions on the correct forum.
https://mbworld.org/forums/c-class-w203-3/
You will have to conduct the below tests using a DVOM to narrow down the problem. To do so remove both covers under the instrument panel and at the left side remove the one Phillips screw holding N19 (small box the size of a pack of cigarettes). Then pull N19 out through the right side and conduct the tests.


