1983 300TD dash vents strange action - PeachParts Mercedes-Benz Forum

dictatorrj · #1 08-27-2007, 12:20 PM

I have an 83 300TD and am having problems with ACC. When I turn on AC via center button I get air flow through all four dash vents, after a short time while driving, I hear a noise from the dash and air flow from the center vents stops and air flow at the side vents increases.

Any Ideas whats wrong.

Thanks, RJ

rrgrassi · #2 08-27-2007, 01:05 PM

Sound like a weak or leaky vacuum pod.

SwampYankee · #3 08-27-2007, 01:28 PM

Quote:

Originally Posted by dictatorrj

I have an 83 300TD and am having problems with ACC. When I turn on AC via center button I get air flow through all four dash vents, after a short time while driving, I hear a noise from the dash and air flow from the center vents stops and air flow at the side vents increases.

Any Ideas whats wrong.

Thanks, RJ

Ditto rrgrassi. Not enough vacuum to hold the diverter flap causing it to close (the noise you hear) and air flow to the side vents to increase.

pizzachef · #4 08-27-2007, 03:46 PM

Is that the pod that's hella hard to get to? I'm having the same problem. I've read of some people who somehow permanently have those vents open...I would love that, but can't figure out how to get that lever to stay pushed in or out...without tearing apart the dash.
Any ideas?

toomany MBZ · #5 08-27-2007, 03:53 PM

Quote:

Originally Posted by pizzachef

Is that the pod that's hella hard to get to? I'm having the same problem. I've read of some people who somehow permanently have those vents open...I would love that, but can't figure out how to get that lever to stay pushed in or out...without tearing apart the dash.
Any ideas?

Must remove dash, I'm afraid.

Shawn D. · #6 08-27-2007, 08:10 PM

Quote:

Originally Posted by toomany MBZ

Must remove dash, I'm afraid.

Not necessarily. I was able to R&R mine by removing the glove box, center right vent, and center rubber vent duct, which gave me access.

Note that a bad dual-diaphragm pod (pink/green) on the left of the case can cause the center vent diaphragm to malfunction, as they share a line.

toomany MBZ · #7 08-28-2007, 06:48 AM

Quote:

Originally Posted by Shawn D.

Not necessarily. I was able to R&R mine by removing the glove box, center right vent, and center rubber vent duct, which gave me access.

Note that a bad dual-diaphragm pod (pink/green) on the left of the case can cause the center vent diaphragm to malfunction, as they share a line.

Good info!

ichbineinekrous · #8 08-28-2007, 11:13 AM

Quote:

Originally Posted by pizzachef

Is that the pod that's hella hard to get to? I'm having the same problem. I've read of some people who somehow permanently have those vents open...I would love that, but can't figure out how to get that lever to stay pushed in or out...without tearing apart the dash.
Any ideas?

remove the glovebox, look for a zinc colored oval-ish cam on the side of the center vents plenum, since yours opens you should be able to see it moving. When it opens just screw a small, 1/8" by 3/4" screw on the left hand side of the cam. Ba Da Bing done. You can either remove the screw as cold weather approaches, or just control air flow with the vents.