MikeC825

Recently noticed during the winter that heat is always coming from air vents,,,,,,no matter where the temperature control is.
Appears I have a vent flap stuck someplace???
This was fine during the cold weather, but won't be nice as weather warms up and I need the A/C.

Any ideas where to start? Turning the temp control down does not change the temp.

Thanks in advance for any help

1999 ML430

Maj. Dundee

Please UPDATE YOUR PROFILE in USER CP to include the year of your ML.

MikeC825

Hi......I just checked all fuses.......all OK ( unless there is a relay that powers it ???)
Before I rip the dash apart, is there anyway to see the vent flapper motor , possibly behind the glove compartment? I would like to verify that is intact and possibly manually change position. I see a photo in a post, but hard to determine exact location just to see it

Hopefully someone has an idea? Thanks

Maj. Dundee

Remove the cover under the driver's side and look up and to the right and you will see the wire cables that control the flaps.

The bottom cable (17) controls the legroom the the upper cable controls the defroster. The eng. does not have to be running to check them.

Turn the dials on the HVAC unit and see if they move properly. You might want to disconnect the cable from the flap doors and move the flaps manually.

MikeC825

Maj. If I am reading this correctly, these cables are for redirecting air to different areas. I will verify them today.

But I was looking for the motorized flap that controls the hot/cold air inlet............as I am always getting hot air.

Maj. Dundee

Let me get one thing straight. Is it that the air is always coming out of the a/c vents and it is always hot?

MikeC825

Yes........and I just pulled the Glove box out and can see the motor and linkage.
When the temp control dial is turned, it rotates fully to hot, but on the return to cold.it stalls halfway.
The linkage can be pushed a little with a screw driver and it will complete its motion automatically. ( next time I am in there, I will slap some grease and see if that helps )
So........now the big question is if I can live with a summer and winter setting by manually pushing it. I left the glove box loose so I can quickly change settings ( 5 minutes in/out)

Unless I can figure out a way to remove the air bag cover without breaking the clips, I don't want to remove it, as I see people glue it back.......I don't want that piece flying off in an accident. And the bag must be removed to replace the flap motor.

There must be a way the dealer removes it or new clips available from the dealer. Does not look like a bad job.........but the clips are an issue.

Maj. Dundee

Mike, you have two separate problems.

The always HOT issue in one thing, probable the Blend Door Motor.

But the direction of where the air comes out of has nothing to do with the Blend Door Motor. The direction of the air is controlled by the AC/Heater Operating unit and the hard wire cables of which I have already supplied you with instructions and illustration.

MikeC825

Maj.......Everything else looks fine......Am taking the car out soon to see if the hot air stopped. Now I need to find out how the dealer removes and replaces the airbag cover.
If the hot air is now under control and the AC blows cool, I will live with a manual Hot/Cold setting until I figure out how to remove those clips without breaking them...or if a replacement is available.

Maj. Dundee

Mike, the air bag cover is part of the Instrument Panel and the tabs/clips that hold it in place are irreplaceable. To change the Blend Door Motor requires the removal of the top half of the Instrument Panel.