Cowel, cowl -- thought that looked wrong.

I think my car was cooked in Arizona before I got it, so it seems every time I need to touch some plastic to fix something, the plastic disintegrates between my fingers...

My new motto for fixing this car will be "first, do no harm..."

 

I have not do this (yet) but as I see Thermo said put your head under dash next to gas pedal and look up behind the radio; I think why don't you remove the radio and look right inside that opening? I might be wrong bot next time I remove my radio, I'll take a look inside to see what's in there?

 

I carefully read through your forums and prayed to God before starting and I successfully changed
the blend door actuator with no problems thank you all and God bless for posting the information.
Jim

 

This is how I solved this problem. I also had a problem with the upper door for defrost. The blend door had broken inside the air box. It was in two pieces. I don't believe this is uncommon. The part is all plastic.
Pulling the entire air box is not an attractive option for anyone. What I did was to open the passengers side of the air box with an electric saw. (I used one of these new vibrating tools. You can change the blades
to a wide variety of blade widths and styles). First of course you want to remove all the blend door actuators. When you remove the top one. The part for the blend door will likely fall inside the box.
I targeted an area around the blend doors mounting location of the passenger side. You want to make this opening large enough to work inside the air box. (as for you purist, the car is 15 years old) I wouldn't
worry to much about keeping this original. It's not an XKE. The first opening I created wasn't large enough and I couldn't put the repaired blend door back in. (note: There are timing issues that need to be addressed).
If I remember correctly. There is a small segment gear that needs to be properly aligned inside the box and the upper blend door has to be in the proper position for this to work correctly. Use care when planning this
out. There are also ledges inside the box that seal or stop certain doors from moving to far. That is where I ran into trouble and needed to make the opening larger. Now I had two pieces that needed to be joined.
Remember to leave enough of an edge on the air box, because you will be making a plate to pull all this back together. Leave at least an inch. Also remember there are things inside the air box that you must avoid.
You don't want to cut through any other parts. That is why I chose this saw. It vibrates and you plunge it into the work. An idea would be to wrap tape on the blade as a stop. This plastic box is only about and eight inch
thick. You will cut through very quickly. You will notice that the bottom of air box is removable (almost). Not really. But by pulling this loose you are able to retrieve any debris inside that falls. Be careful. The air conditioning Evaporator is in there.
The best way is to cut the side section out in one large piece, going around all three blend door motor mounting points. Remember to not go all the way over to the corner of the box. This would make the air box unstable
and difficult to repair.
After you have cut out this section you can clean up all the debris and make the needed repairs to the blend door. You can use a special type of Plastic epoxy. The part is a poly resin and is difficult to bond. A bonding
material that guys don't often consider, would be the bonding agents women use for their fingernails. It's a two part process. You apply the powder in the area to bond and apply a few drops of this activator. You can work with
this material for a little while. But when it cures. It's a very strong polymer bond. I used a combination of techniques to repair the door on mine. I believe I had to pin the parts back together and then bond them.
My door broke in a twisting motion. I'm sure that is not unique either. Allow the bond time to cure. Test your repair. You don't want to be going back in there.
Make no mistake. This upper blend door is tricky to install. There is a ledge it stops against that you need to get over. Make sure the door moves properly to the upper position.
Now your ready to fix this cut out side, back in place. What I did was to make a template of the piece and then using a piece of sheet metal. I cut out a piece the would overlap each edge about 1/2 inch. Drill some holes.
Use small sheet metal screws to fasten it all down. I then shot a coat of flat black paint on the whole thing. The fix worked great a I haven't had a problem since. The damn thing should have been designed with this
access door. Now I can get in to this air box easily.

 

Did you replace the side with metal or use metal to hold the box back together? How big of a hole did you need to make? Since it's the defrost couldn't you go from the driver's side on the left hand drive?

How big is the defrost door? I was thinking about windowing my hvac box from the left side just around the defrost door (mine is stuck with broken door).

 

I had the broken defrost flap, had to stick a scope down to verify it was broken so I gambled I could fix it from the driver's side (left hand drive). I documented the process too. I cut around the left side big enough to get the flap out and my hand in to retrieve the other part of the broken shaft. I did not have to remove the steering wheel or even the knee area of the dash. I used a multi saw (cuts with vibrations) and a plastic welder to repair and jbweld plastic bonder (onky one one rated for thermo plastics). It took a few hours (including waiting for epoxy to cure) and it was back in business. Uswd epoxy to reinforce the flap too.

 

I sounds as if you were able to manage this. My approach was different due to my size and eyesight. The Right side of the air box is well exposed. I can definitely see the advantages to going in on the Left side.
Did you cycle the blend motors before you put your flap back in place. These motors do have an alignment notch. But sometimes, these motors act up and don't stop in the right place. I'm guessing that it is how
these blend doors get broken.
I had tried to email you a reply earlier in the day but the email kept coming back unsent. Couldn't find address. I don't know what that is about.
Anyway. Glad it all worked out.

 

The alignment was simple but you can find the stop inside the box, the defrost flap hits a had stop on the left side, which appears to only catch that side leading to twisting of the shaft. Yes for safety you should run the drive to its stop on motor in thst same direction then install the drive back into the flap when it's already in thst position.

The defrost is sort of flexible and over time that flex makes it break.. I plastic welded mine back into one piece (using a plastic welding iron), then reinforced it woth jb plastic bonder since it's thermo plastic rated. That flap is made out of a thermoplastic of some kind, (I know it's not pp).

You inspired my left side attempt and if you look the left side kinda gives you a hint at the locsrion of the sweep and stop, as well as the exposed other pivot. On mine the housing was also binding the shaft which I had to deal with too on the right side. Clearanced that just to be smooth and used some light grease to be sure of continued operation.

 

I don't actually remember what type of bonding agent I used. I do remember that some of the first attempts at bonding these two parts back together, did not work. Whatever resin I used, did not
bond to this polypropylene type of material. I ended up drilling a few holes here and there to tie the parts together with a braided thread before bonding them. Along with metal pins inside the main
pivot point. I believe I used a combination of CA and Plastic epoxy. And I seem to remember using graphite as a lubricant. Grease can attract dirt and debris.
Either way. There's more than one way to skin a cat. You've got this under control.