ben73

Hi All,

I have a problem with my '05 E55 where condensation forms on the windshield regardless of where the knob is positioned that controls where the air is supposed to go.

I had read about this problem here before and assumed the vent motor was dead and I would soon be changing it...

However!!... Today I pressed the demist button and was very surprised to feel the air that caused the condensation stop blowing on the windshield!! It worked correctly on the other side of the windshield though.
So it appears my vent motor is not dead, but working in reverse! Air is directed to the windshield during normal operation, and not while in demist mode!

So is it possible to calibrate the position of the vent motors?

I vaguely remember reading a thread where the mechanical stops had broken off the heater case and allowed the vents to move beyond their intended range and wondered if this was what I was experiencing. I cannot find the thread now, and it's possible that it wasn't even written about an E-Class, so maybe irrelevant.

Any ideas before I pull the dash apart?

THANKS!

Baltistyle

I'd really like to know the answer also. It seems as though two motors might have the wrong wires plugged into them from previous work. Is anybody else had this issue where the defroster is open only on one side when it is supposed to be closed and closes when it is supposed to be open. This would indicate that the motor works properly but in the wrong position for the climate control only on the right side.

i've not been able to find any information and would love to have an answer without pulling apart the dash as well.

ben73

I guess you have the same prob?
I know the history of my car and the dash has not been pulled apart before.
I'll have a STAR laptop soon, and I believe it's possible to manually drive the vent motors to test them, so I'll be doing that before I rip the dash apart.
I'll let you know what I find

badmwhite

Mine does the same did you find anything?????

Baltistyle

I nor the original poster have been able to fix this yet. What I have found is that the limits need to be set by star. Seemingly our actuators/solenoids are fine just not synced correctly. I am not sure if there is any sort of HVAC reset ( I have found suppose it things that work, but have not tried ) we can do with this vehicle so any others that read this and can chime in, please feel free to do so. My default has been to keep my right hand side climate control vent position adjustment switch in the 930-ish position.

ben73

I haven't had a moment to get back to this.
I have my Star setup working now, so I'll try to check it out over the weekend..

ben73

I had a quick play with this today.
i found a test in Star and this was the result..

The vent in question is the upper one. The result is way out of the green zone at the extreme RH end of the scale.
It's a shame there doesn't appear to be a function to manually calibrate the position of the vent motor because it does work, it just needs to be told when it's on the windshield and when it's not.
I'll try to have a more thorough look tomorrow..