gh3382
Senior Member
- Joined
- May 5, 2012
- Messages
- 180
- Reaction score
- 41
- Location
- North East England
- Your Mercedes
- W164 ML350
I have a heater problem that is doing my head in .
I cant get any fan powered or any warm air out of the centre vents or any warm air at all from the rear centre vents or under the front seats into the rear seating area.
I can only get heat in the front drivers window vent if I turn down the drivers side heater dial to minimum and turn the passenger side heater control up high well above the current ambient temperature in the car. I also get heat and blower if I turn it on in the passenger side when I do this and I also get heat into both sides of the footwell but not to the rear at all or out of any of the centre vents no matter what speed the fan is set at. Pressing the rear area button on makes no difference.
My local independent has no fault codes on the star system and we have changed the heater control unit on the dash twice with no effect .
There is not any change to this behaviour if the air con is on or off no matter what setting I have the fan set at which seems to be acting ok . You can hear all the different levels of speed of the fan changing and feel the difference in power. Changing the 3 buttons for the defrost, face level and footwell does not alter the behaviour either they to seem to work as you would expect them too including the rapid defrost which works as you would expect. I have no electrical problems elsewhere.
The Independent did realign the heater flaps on his Star computer with no change to the problem or error codes shown.
I am now left with the following to consider after reading extensively on the internet. The flap linkage,(which could be broken) the actuators which I believe there are eight in series and possibly the sensors which are around the car which I doubt. All relevant fuses etc have been checked.
The linkage and actuators looks like a big job as for the strip down to access them.
I would appreciate any help or ideas on this.
GH 3382
I cant get any fan powered or any warm air out of the centre vents or any warm air at all from the rear centre vents or under the front seats into the rear seating area.
I can only get heat in the front drivers window vent if I turn down the drivers side heater dial to minimum and turn the passenger side heater control up high well above the current ambient temperature in the car. I also get heat and blower if I turn it on in the passenger side when I do this and I also get heat into both sides of the footwell but not to the rear at all or out of any of the centre vents no matter what speed the fan is set at. Pressing the rear area button on makes no difference.
My local independent has no fault codes on the star system and we have changed the heater control unit on the dash twice with no effect .
There is not any change to this behaviour if the air con is on or off no matter what setting I have the fan set at which seems to be acting ok . You can hear all the different levels of speed of the fan changing and feel the difference in power. Changing the 3 buttons for the defrost, face level and footwell does not alter the behaviour either they to seem to work as you would expect them too including the rapid defrost which works as you would expect. I have no electrical problems elsewhere.
The Independent did realign the heater flaps on his Star computer with no change to the problem or error codes shown.
I am now left with the following to consider after reading extensively on the internet. The flap linkage,(which could be broken) the actuators which I believe there are eight in series and possibly the sensors which are around the car which I doubt. All relevant fuses etc have been checked.
The linkage and actuators looks like a big job as for the strip down to access them.
I would appreciate any help or ideas on this.
GH 3382
