855 1995 Manual Climate Control no defrost

Svenska 850 Wagon · Post by **Svenska 850 Wagon** » 28 Dec 2007, 22:00

Has anyone had it where the top position on the dial does not work? The defrost? This is on the manual climat control. It was getting harder and harder to switch it to this position and then it went easy. I have a feeling something has come loose. A little air blows out but not much at all. Kind of like it was on the floor or vent position. Easy fix? Not sure if I have to rip the whole dash out.

It takes forever to defrost which is no fun in winter

Thanks

Post by **Ozark Lee** » 29 Dec 2007, 07:15

I sounds like one of the damper doors got stuck or one of the mode control cables siezed up on you.

Easy fix - unfortunately not. Because of the way the cable are routed in the manual climate unit it is a real PITA to remove and service. Not a full dash removal tough but figure on a few hours of saying bad words.

The first step in diagnosing the problem is to remove the lower dash panel on the driver's side of the car. On the side of the climate unit there are three mechanical cables that articulate the driver's heat damper and the floor and defrost dampers.

You can easily see which one is the temperature damper by rotating the temperature knob and seeing which lever moves.

The other two levers should move up and down in opposite directions as the mode knob is rotated.

Based on your description I am going to guess that only one of the levers will be moving. This points to a broken cable (not likely) or a broken cam in the mode control part of the control head.

If both of the levers on the side of the climate unit are moving it points to a problem with the damper door itself. That can be a very tough fix if the damper broke internally - inside the climate unit.

Take a look at how the levers operate as you rotate the knobs and post back a description of what you find.

...Lee

Svenska 850 Wagon · Post by **Svenska 850 Wagon** » 29 Dec 2007, 14:33

After some more playing around I managed to get it onto defrost. I applied preassure on the knob and then it came on. The Dial is slightly to the left of Defrost at about 11 oclock. I guess the part behind the knob is wearing?

Post by **Ozark Lee** » 29 Dec 2007, 15:03

I guess the part behind the knob is wearing?

The mechanism that controls the doors doesn't really wear per se. I suppose the joint between the knob and the cam could wear and get loose.

If you haven't already done it grab the manual pinned at the top of the main 850 page and see the file named ac heater system manual.pdf

They outline a procedure to adjust the end length on the control cables to get the doors back in sync.

Good to hear you at least got it to work.

...Lee

Svenska 850 Wagon · Post by **Svenska 850 Wagon** » 29 Dec 2007, 22:30

Thanks Lee !