heater/blend door/Hack fix? - Ford F150 Forum

Ryano · 11-15-2009, 06:13 PM

I have a broken blend door in the 99 f150, I have already chopped the heater case to get the door out. I then just stuffed the hole with rags to make the air move through the heater core and into the cab, defrost doesn’t work to well. This was just a quick fix.
I’m going to try to glue the parts back together and make it manual operated, by a cable (the old schol way)!

Anyone else done this?

If anyone has a old door actuator (pictured stepper motor) I could use one to gut and use as a guide for a homemade axal and a support for a cable attchetment. Email or post here.

Ryano · 11-15-2009, 07:38 PM

I got most the pieces glued back together, would like to re-enforce the outer part of the door axle at the broken end, maybe 5/8ths PVC cut in half then glued. Don’t know if PVC and ABS plastic will bond, so I’ll have to test it on something first.
The homemade axle that installs where the stepper motor shaft once did is softer plastic then ABS plastic so I installed one of those wall anchors things into the end of the tube for a tighter fit. I used no glue at this location. It will slip before it would brake the door
A shampoo bottle was used for the tube axle (pictured already cut) probably something else better but I had to start somewhere. Post more when I know more!

Ryano · 11-20-2009, 12:21 PM

We upgraded are tempory fix for emergency heat by removing the rags that were stuffed into the AC port in the air box, we replace this with some 1/8th " paneling and gray taped it in place. Has worked well all week . Now we control temp by fan speed and window rolled down a bit. This will buy us some time for the fix.
While we were doing this we took some pictures of where the door mounts inside the box. We also cut the tabs off the broken door and glued the broken part of the orignal door . Still need to figure some way to hold the glued broken door in place so it dont fall out of its mounts but will move from under the dash manually. We have no plans to use the actuater motor (stepper motor).
Ideas welcome !

Note there seems to be a difference between 98 and 99 , I seen a post where a 98 replacement door comes with a plastic frame for the door , I dont belive the 99 has this.

Ryano · 11-23-2009, 10:19 AM

Had a chance to get some more done this weekend, I took the box apart again and installed the broken door an got some measurements. With the broken door installed it swiveled freely and stayed in its box supports molded into the air box. If your plastic door brakes the way mine did you may get some more use out of it manually moving it to a seasonal position. A good way to fasten it would be with Velcro self stick material.
There is no way you are going to install a new factory door into the air box without removing the dash to get access to the box cover. A new factory stock door will be about 9" long and you have 8" to work with, if you try it you will probelly brake it. The heater treater door is a much better choice.
Here are a few pictures of the broken factory door in its open and closed positions. Also some measurements.
Biggest problem im have is finding compatible glue for the ABS plastic.

Post more when I know more!

Ryano · 11-23-2009, 11:36 AM

add

Ryano · 12-01-2009, 12:24 PM

Got some more done this week! The good news is JB Weld (orginal) is compatible with ABS plastic and worked well. The bad new is I lost 1 of the broken pieces. I’m going to try it anyway with the piece missing. Should still work for manual operation of the blend door.
I tested the jb weld on the back of the door just to see how well it worked. I did this in two spots, one spot I sanded and the other I didn’t. The weld works much better in the sanded spot. The way the door is made makes sanding a big job so I used a dermal tool with small disks. With the plastic ruffed up I applied the JB weld in layers building up the axle. Had to allow 3 hour drying times between coats. Here is a picture of the door in a jig I made for the fit.

The manual door handle! (below)
Its made up of a piece of 3/8’s tubing and a 1/4" keyway JB welded into the tube. The washer that fits to the end of the key way is from the back of a GM alternator designed for a square bolt , you will half the cut some of it off for the square fit of the keyway. I then JB welded it in place, the idea here is to make the washer flat for a piece of Velcro material to stick to. Another piece of Velcro will be placed into the axle shaft to make the connection of the two pieces.
Thats where I’m at now, post more when I know more.

Ryano · 12-08-2009, 04:09 PM

Got a little more done!
The altered door axle end was filled with jb weld and sanded flat to accept the self stick Velcro (female) material.
The homemade door control handle was also sanded flat and the Velcro (male) material was stuck to the end.
Now the 2 pieces were mounted into the jig for a strength test of the Velcro connection and the strength of the jb weld factory blend door. The test was to move the door manually using the homemade handle and push 2 twelve oz full cans of soda , the distance of the door sweep. It did this with no problem at all. The Velcro is very strong.
Next I mounted 2 small magnets to the center of the door at its outer edge, I used jb weld to hold them in place, I cleaned the surface of the ABS plastic with adhesive cleaner first, then sanded.
Now I need to move out to the truck and get something into the door sealing gasket for the magnets to attract to for the full AC position and the full Heat position.
Making all this adjustable is still in the think tank! have a few idea’s !
Here is a few pictures.
Post more when I know more.