OK, now that it's a little chillier, I'm paying more attention to the climate controls. I noticed that no air will blow from the left, foot well vent. The right side works fine, pushing the director button does in fact, change the flow of air.

On the left side, the director button will send air out of the panel and the defrost as it should but when you select "floor only" you can hear the fan racing like it's cavitating and pushing against a closed flapper/valve or whatever changes the course of the air stream.

Is there some kind of actuator that opens the flow to the floor? If so, is it vacuum or electric? Is there some kind of control rod that may be dislodged? Is this one of those problems I hear about where people fix it be re-soldering some connections?

I just want to have a little background before I start taking things apart looking for the problem.

Thanks, my feet are cold!

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

There is an article I cant locate at the moment written by SteveBfl concerning AC diagnostics. In it is a test for flap controls initiated from your CCU. They are vacuum operated.

The other wiring issue you are remembering concerns the blower regulator; not your issue.....at this time.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

When my turbo wastegate actuator solenoid was acting up I also noticed the ACC was acting weird and doing something similar to what you are describing...I'd assume that the vacuum was leaking at the solenoid and causing the ACC doors to not operate correctly so you may want to start by inspecting the vacuum hoses under the hood, passenger side, near the firewall. If you are lucky you will find the problem is there and not in the ACC box behind the dash.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

just a guess, but is there any possibility that one of the cabin filters is clogged, and not allowing air to pass through? I do not know the exact layout of the heater box or control mechanism, so I don't know if a clogged filter would affect just one side of the vehicle. Good luck...

Hope this helps.

http://www.eclassbenz.com/acdiag

well even found it by you!!!

TMAllison
Registered User Join Date: Feb 2004
Location: Walnut Creek, CA and soon 60°52'53.93"N, 150°49'39.24"W
Posts: 1,803

Am sure some techs will chime in Monday. In the mean time this link will provide some info to explain the codes.

http://www.eclassbenz.com/acdiag
__________________
Terry Allison
N. Calif.

85' 300d Turbodiesel 311K (not counting right now)
99' E300 Turbodiesel 221K and counting (14 of 20 o-rings now viton)


Climate control error code help - need sensor?

__________________
raMBow

1999 E300DT Obsydian Black Metallic, Heated Full Leather Parchment options, E2, K2, 136,000+, best 36.5 mpg - GP's 12-04 & 11-12 Zero Stuck
2010 Honda Odyssey - The BrideMobile - best 26.5
(2) 2005 Honday Accord- (1 -Corporate 1 - Personal) - 110,000 4-cyl 30mpg
2000 VW Golf GLS TDI, Upsolute Chip (sold to Brother, now 300+k on it) 48.5 mpg like clock work
1987 Honda CRX HF - Sold 87,000 always over 50 mpg Max 67 mpg

to get the codes for the above link, go here first..

http://www.eclassbenz.com/node/27

__________________
raMBow

1999 E300DT Obsydian Black Metallic, Heated Full Leather Parchment options, E2, K2, 136,000+, best 36.5 mpg - GP's 12-04 & 11-12 Zero Stuck
2010 Honda Odyssey - The BrideMobile - best 26.5
(2) 2005 Honday Accord- (1 -Corporate 1 - Personal) - 110,000 4-cyl 30mpg
2000 VW Golf GLS TDI, Upsolute Chip (sold to Brother, now 300+k on it) 48.5 mpg like clock work
1987 Honda CRX HF - Sold 87,000 always over 50 mpg Max 67 mpg

Actually, those folks kind of borrowed Moderator SteveBfl's work and created that site.....here is Steves article.
http://www.continentalimports.com/ser_ic40142.html

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Thanks for the replies everyone, that's some good reading. My car has a bunch of codes but all are unrelated to the problem. The car was serviced for AC problems prior to me owning it and I think they never reset the codes.

Interestingly enough, the actual problem was the one I had envisioned in the begining. Since it's nice out today, I decided to do a little exploratory surgery. I pulled the pad from up under the dash to expose the floor vent and controls. With the engine running, I cycled through the different settings to observe the behavior of the flapper valve. I could hear something moving/clicking but the flapper never moved. Reaching in with my finger, I gave it a little push and it appeared to be swinging freely and not attached to anything.

I found a small mirror and positioned it so I could see up the vent passage and sure enough, the control rod from the vacuum actuator had popped off it's connection point on the flapper valve. All I had to do was stick my fingers up the passage and snap the connector back on. That easy!

I put it through it's paces a few times to make sure there wouldn't be a repeat failure and the buttoned it back up. In the end, if I'd known what I was looking for in the first place, I wouldn't have needed to take off the pad. You can get the same access by simply removing the vent cover.

I think what happened to cause this was that someone shoved the cover back on with the vent flapper in the "floor" position which leaves it vulnerable to damage. From what I can tell, the cover should be installed when the flapper is in the "defrost" position which moves it up and out of the way.

I took a couple pictures if anyone's interested. I just have to find my sync cable!

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

The best kind of repair...easy and FREE! Good work. I'm sure a dealer would have found a way to charge $500 to fix it for you.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Here's a couple shots I took (now that I found my cable!!!)

This first one just shows the floor vent and the vacuum actuators in blue and red. You can see the flapper with it's white edge in the vertical position. It pivots on the round, white stub seen in the middle of the picture.



The second shot shows the view up the vent tube via a small mirror. You can see the flat metal bar that I was able to re-link to the flapper. It was simple as pinching it back together.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250