A/C comes out of defroster when it's over 80 degrees! - PeachParts Mercedes-Benz Forum

murray350sdl · #1 07-03-2008, 03:03 PM

Anyone ever experience this. I've only had my 1990 350 SDL since last September. The freon is fully charged and the Climate Control does everything it's supposed to....except, when it's over about 80 degrees outside, the A/C will ony come out of the defroster, side vents and rear vent. Once it cools down outside to below about 80, the climate control switches the air to all the dashboard vents as it should. ???? Any ideas???

TX76513 · #2 07-03-2008, 03:11 PM

There is a vacuum pod that controls the defrost flap, its worn out. Very common problem. If you do a search here on the forum for "Vacuum Pod" you will be enlightened.

murray350sdl · #3 07-03-2008, 03:22 PM

hey - thanks! i'll check it out. one other thing, if i push the defroster button, I don't get cooled air, i get hot air?? could it be the mono valve?

TX76513 · #4 07-03-2008, 03:23 PM

Quote:

Originally Posted by murray350sdl

hey - thanks! i'll check it out. one other thing, if i push the defroster button, I don't get cooled air, i get hot air?? could it be the mono valve?

You will not get cold air by pushing the defrost button only warm/hot air.

murray350sdl · #5 07-03-2008, 03:26 PM

Thanks!

daw_two · #6 07-03-2008, 04:34 PM

Quote:

Originally Posted by TX76513

There is a vacuum pod that controls the defrost flap, its worn out. Very common problem. If you do a search here on the forum for "Vacuum Pod" you will be enlightened.

And did I change mine when I had the dash out??? NOPE. It's been fine. Now, that I have my beautiful dash in my car, what do you think has happened twice? Yep --- AC out of the defrost vents. I'm trying to verify that it only happens when I hit a big bump (possible solder connection in CCU?). I haven't pinned down the corelation, YET.