this is for the 350sdl.

the 'vent direction' seems to be stuck on 'defrost' i.e. the feet and face vents don't work and only the vents below the windshield seems to work.

i did research on this and found out that the vacuum operated valve that controls the direction of air is broken. my question is...is there a way to permanently adjust the position of the vents to the 'face' only ?

the reasons of course are economic until i get out of school.

thanks in advance guys.

__________________
Jennifer
90 350sdl

Hey,
I had a similar problem but the actuator wasn't broken. It was just disconnected fron the damper arm. I popped it back in and it worked fine.

Hopefully yours isn't broken either.

Danny

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1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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how about posting a procedure if you don't mind?

__________________
Jennifer
90 350sdl

Hey,
I was actually working on replacing my expansion valve for the AC system. I looked over in an opening in the center console and saw an actuator. So I figured, let me go and get my handy Mity-Vac and check that sucker out. As it turned out it worked fine. The actuator arm was just disconnected from the damper arm.
Other than that I'm sorry to say there is not much of a procedure. It only took couple of seconds to reconnect it.
I need to get back in there because my rear vent is always blowing. My actuators are all lined up behind the center console. You have a later model but I can't imagine there being too much difference in the placement of these things.

Danny

__________________
1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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(='.'=) This is Bunny. Copy and paste bunny into your
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Jen,

How do you know the control valve is not operating? Did you remove the right panel from the center console and check it? I think is is vacuum relay #4 of the 6 relays lined up one on top of each other. The vacuum pod itself is above the accelerator pedal. You have to remove the panel under the steering wheel.

What I did was to remove the line connected to the relay output and connect it to a Mity-vac (Snap-On actually) and apply vacuum. This will verify if the vacuum pod will hold vacuum and open the flap for center vent air-flow. Try this with the blower motor on and verify the air-flow. If you have air flow, then the either the relay is not working, not getting vacuum, or the temperature control module is not turning the relay on.

You can then disconnect the electrical connector to the relay and put a voltmeter across it. With the AC turned on (The only way I know to ensure the center vents should be on), the meter should read battery voltage. (~14.1V) Don't find another ground point for the meter and just probe with the positive lead, as I think this relay is turned on by the controller by applying ground, not battery.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
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