FLASHBACK

My problem is that no (fan) airblower is working, in the display it indicates all the different speeds but no blowing of air not from nor rear.

I read these errorcodes out with the AutoLogic device:

AAC : AUTOMATIC AIR CONDITIONING
9000 (B1000) [Current] Aac push button control unit faulty

AAC : Rear automatic air conditioning
9429 (B1429) [Current] Right duo valve (A31/1y2).

Is it possible that it just the blowermotor or the motorresistor that is defective? Or do i have to get out my wallet for the controlunit?

I havent yet tested with power direct on the motor but will do so in a couple of days.

vincheung

I had the same issue a couple of weeks back but didn't pull the same codes you have. I started the diagnosis with fuse checks, then I got under the passenger dash and removed the blower motor (regulator attached to it). You can give the blower motor a bench test to determine whether it is working or not. If the motor works then I would say its the regulator which needs replacement (i think its about 50-60 bucks). I included a link to another thread, hope this is helpful.

For me, I had downtime at the office so I took the motor to my office, cleaned it up and lubricated it, plugged it back in, spun for barely 3 seconds and I determined it was the motor so ordered a new one. Now everything is back to normal. I would recommend that while you are in there, replace the cabin filter as well. I would recommend a headlamp, safety glasses, lay towels down flat after you fold down the carpeting in case you drop screws it wont fall into the abyss, and small screw driver (T20 torx) makes life easier in that cramped area. Also, set the passengers seat all the way back and pad the foot rail area with a bunch of towels too, will save your back. Breaking it down took about 30 min, put back together in 20.

https://mbworld.org/forums/s-class-w...procedure.html

FLASHBACK

Blowermotor replaced, no action from that one!

I will get back with info on if it was related to the rear ac as well.

kraut56

is the little red light in the AC button on all the time and can't be turned off?

vincheung

@flashback, note the error code displayed in the climate control and give it a reset. After I changed out my blower motor, I cleared the code and it hasnt returned since. Everything has been normal ever since, AC, Heat, all fan modes work properly.

tusabes

how do you reset and clear the code ? Do you need star DAS ?

FLASHBACK

Message no 1 is gone, front blower and heating system is working as supposed. Reset the ac error codes BUT still code 1429 remains..

When reading OBD with AutoLogic it says: AAC : Rear automatic air conditioning 9429 (B1429) Right duo valve (A31/1y2)

If the right douvalve is malfunctioning could that render the rear blower nonfunctional?

kraut56

No - but understand that depending on the programming the rear ac may only work if a seat in the back is occupied.