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CBChadwell

Defroster Problem

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The defroster on my '90 Reatta is not working.  Everything else with the heating system seems to be working just fine but there is no air reaching the windshield when on the defrost setting.  I figured it is either a malfunction of a baffle in the AC/heating system someplace or a malfunction of the electronic climate control panel.  Has anyone else had this problem and if so how did you fix it? 

 

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Does air come through the vents when you switch it to them, (not defrost or floor but bi-level) if not then the mix door that controls the direction of the air - the arm may be broken.

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I checked for a loose or disconnected vacuum line under the hood as Harry Yarnell suggested and didn't find one although one could be loose behind the glove box.  I'll check that out later.  In answer to Scott's '90's input,  here's what I found:  on DEF—some air comes out of the floor vent but most comes out through the upper vents and none or very, very little out of the defroster vent.  When on HTR & ECON, same as for DEF, most air comes out the upper vents. In other words, changing settings doesn't seem to have any effect on where the air is directed to.  Now what? 

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If the air is coming out as it should but is low volume then you need to clean inside air box where the blower fan is located. There is a grated item [can't think of the name] that is probably loaded with gunk that is blocking the air flow and needs to be cleaned.

 I cleaned mine using a garden hose with a sprayer, then air from a compressor [low volume to dry out the water] then carb cleaner. Repeat until it looks clean. Everything should drain out the bottom as you clean. I used a "night light" as my light source. 

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There is a good set of instructions on cleaning  the air flow in a thread called "Air Filter " I would put a link to it but I don't know how

 

 

 

 

 

 

 

 

 

 

 

 

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Can someone tell me what the technique is to get the connector off the back of the Electronic Climate Control module?  I've tried pulling it off but it doesn't seem to want to pull off.   I don't want to pull too hard for fear of messing up the connector.  I can't tell if it has a locking pin or not.  Any help would be appreciated.

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Duh, I finally figured it out that the little black tab was the locking pin and once that was depressed it slipped right off.  Sorry. 

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This is a five or six year old thread regarding the climate control repair, which wanders around a bit trying to understand the inner workings of the HVAC controller, and that is my guess for your problem. With no vacuum to the system, the air direction defaults to the defrost position, just the opposite of what you are reporting. If you are willing to access the controller in the right side dash, standing vertically, connections on bottom, you can run the various air doors manually with a vacuum pump to see if they work. Either the defrost/vent door is stuck or the controller is sending vacuum to the door holding it in the vent position. The FSM assumes the HVAC module in the dash is functional of the indicators change as per your input:

 

 

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11 hours ago, CBChadwell said:

I checked for a loose or disconnected vacuum line under the hood as Harry Yarnell suggested and didn't find one although one could be loose behind the glove box.  I'll check that out later.  In answer to Scott's '90's input,  here's what I found:  on DEF—some air comes out of the floor vent but most comes out through the upper vents and none or very, very little out of the defroster vent.  When on HTR & ECON, same as for DEF, most air comes out the upper vents. In other words, changing settings doesn't seem to have any effect on where the air is directed to.  Now what? 

 

Sorry I didn't mean to jump to conclusions - Check the other things suggested above and let us know what your results are.

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Well, the defroster problem still exists.  I can find no vacuum leaks, I've cleaned the Climate Control Module as per the instructions from Barney Eaton.  I looked for the instructions on cleaning the air flow as per Phils38cpe's comment but couldn't find anything on it.  I did have a mouse build a nest in the blower housing once and recently I thought I smelled a dead mouse in the car so it's possible a mouse could have plugged up some air passage.  If anyone knows a cleaning procedure for the air ducts, please let me know. 

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On 3/10/2019 at 7:33 PM, SCOTT's 90's said:

Does air come through the vents when you switch it to them, (not defrost or floor but bi-level) if not then the mix door that controls the direction of the air - the arm may be broken.

The mix door is different from the defrost diverter door but I think we have the same arm in mind.

 

It's possible the arm on the diverter door is broken or stuck. Usually when it breaks the door is stuck in defrost but I guess the door could stick in the position where only air comes out the vents too.  If this is the problem it's not an easy fix.

 

Air Diverter Lever-5.JPG  GEDC0268.JPG

 

GEDC0267.JPG

 

Thanks to whoever posted these photos previously. I believe it was John (machiner55) but I'm not sure.

 

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I didn't know for sure but when it first happened my first thought was that it was a broken or disconnected lever or arm as Ronnie described.  The pictures were very helpful, thanks.  As Ronnie said, it looks like it would not be an easy fix.  I'm 78 years old and trying to do under the dash kind of jobs don't appeal to me a whole lot.  I've had the car for about 21 years and although I have other cars, I still love it and use it a my-go-to car for local transportation.  As my wife often teases me when something else goes amiss with it, "but it sure is a pretty little thing, isn't it". 

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Machiner 55 went through the center dash vent and wrote up a tutorial on it. If you have an '88/89 you can pull the dash and replace it. It is a bit involved the first time you do it but gets easier the more you do it. I've done 2 of them but one dash came out twice more as we were looking for a short.

 

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Thanks Ronnie for clearing that up, I couldn't remember what it was called.

 

Mine is broken and like you CBChadwell I have foregone the idea of tearing into the dash to fix it so I just live with it the way it is for now.

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