My heater has stopped blowing air on the floor, it only blows up on the windshield. Can someone tell me what actuates the flapper door (deflector) that diverts the air flow direction. Also is this door accessible so that I might be able to use a wire to manually push or pull on it to change it's position to break it free from whatever it is hung up on?
I suspect the door is stuck because when it did work you could hear it sort of "slam" when it changed direction as if it was hung up on something.
I did push all of the buttons on the dash one at a time and none of them made a change.

That sounds to me like you have lost your control power to the ACC system. When power is lost it defaults to maximum heat, maximum fan, and the flaps default to defrost position.

This is fed from fuse 7 in my 1987 wagon, not sure if they kept that consistent through the 124 to the end.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

The fan speeds low,auto and high work fine.I checked and all fuses are good.

The flaps are controlled by a set of vacuum/electric solenoids, located just to the left of the glove box or airbag. Remove the glove box liner or the air bag and you will see the solenoids lined up in a vertical row. Each solenoid has a plastic vacuum hose leading to one of the flaps and there is a vacuum line feeding the entire solenoid set. You can remove the lines one at a time and test each one with a Mityvac or other vacuum source. Any line that won't hold vacuum is connected to a flap with a broken diaphragm. It is likely that your floor-heat flap is one of those.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Jeremy,
is there a trick to removing the air bag?

Packerfan, there is one bolt holding the airbag in. It is accessed through a hole in the underside of the dash. You need a 10mm socket on an extension to remove the bolt, then the airbag will come out.

I hope this helps, Robert

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Mercedes Benz Master Tech - Retired

Thank you Robert, that sounds easy.I like easy!

Disconnect battery before disconnecting air bag.

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Jim

I'm glad you said something Jim.............I guess I could have ended up in the back seat.......BOOM!

well heres what I did. I pulled out the air bag and found what looks to be a manifold with a vacuum hose at the top and maybe seven lines going down. I pulled the hose off the top and attached a remote vacuum source in place of it and pushed the climate control buttons and everything seemed to work fine, hot air was blowing on the floor. I put the original line back on and nothing would work. I was not able to test the others one at a time because there is no room to get my fingers in there.

Then perhaps the ACC controller (aka the PBU, push button unit) is not signaling the manifold. If there is power to the PBU, perhaps it has failed and needs to be replaced?

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Where is the flap door located that directs air flow to the floor?
I would be happy wedging a piece of wood or something in there to keep it open.

Speaking of Airbags i was looking them up for my 1995 E300 as well. They are still available (in black only), but wow...$1,400 for passenger side, $2,100 for steering wheel.

Looks like mine expired in 2010 according to the jamb sticker!

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1995 E300 (W124)
1999 ML430 (w163)
2011 GL350 (x164)
2016 Sprinter 144" 4X4 lowtop (906)
2004 E500 (W211) 4matic Wagon (Gold)
2004 E500 (W211) 4matic Wagon Avantgarde (silver)

make me an offer on passenger side, I might sell you mine if you are interested.

Only kicker is how old are yours! If original they are the same as mine,

Does the door jamb sticker show updated on yours?

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1995 E300 (W124)
1999 ML430 (w163)
2011 GL350 (x164)
2016 Sprinter 144" 4X4 lowtop (906)
2004 E500 (W211) 4matic Wagon (Gold)
2004 E500 (W211) 4matic Wagon Avantgarde (silver)