98 Eddie Bauer Blend door question

[98eddieExpo]

Is the EATC blend door the same as the non-EATC blend door? We bought a 98 Eddie Bauer 4x4 a few months ago and having some A/C issues. It's good on charge, has good airflow, and the suction line/accumulator gets very cold, but the vent air temp isn't great and gets worse when driving. It'll be passable when idling though, so I don't know if it's a notorious blend door issue or a heater valve issue (I'm going to put a ball valve in line with the heater core hose tonight and see if that helps any).
When I put the climate control through its little self test it gives no codes and I've verified the actuator is moving, and I plan to clean out the evap core sometime this year too. I do refrigeration work for a living so I do understand basic refrigeration.
EDIT: Clarification

 

[amj441]

The evap core does get full of leaves, pine needles and dirt and cleaning that off does help a ton with vent temperatures.

Here is post from just a little ways back that confirms that the blend door motors are NOT the same, BUT the blend doors are: 1997 Explorer EB SOHC AWD

And heres another with bit of information on how to clean the evap core:

1997 Explorer Ltd. Automatic air temp heater box cleaning / seeds / dust

Hi all, had the blower motor out before and found a bunch of seeds from either a tree or who knows, no mouse nest material, cleaned it out before winter and got in as far as i could, now with winter over, im still getting some debris coming through the vents, so either it was frozen, or knocked...

www.explorerforum.com

 

[98eddieExpo]

The evap core does get full of leaves, pine needles and dirt and cleaning that off does help a ton with vent temperatures.

Here is post from just a little ways back that confirms that the blend door motors are NOT the same, BUT the blend doors are: 1997 Explorer EB SOHC AWD

And heres another with bit of information on how to clean the evap core:

1997 Explorer Ltd. Automatic air temp heater box cleaning / seeds / dust

Hi all, had the blower motor out before and found a bunch of seeds from either a tree or who knows, no mouse nest material, cleaned it out before winter and got in as far as i could, now with winter over, im still getting some debris coming through the vents, so either it was frozen, or knocked...

www.explorerforum.com

That is exactly what I needed to know!! Thank you so much!!!

 

[410Fortune]

Yes they are physically the same door and hvac box
The actuator is the only thing that differs analog to digital climate controller

You can use a dental mirror or the camera on your phone to look down at the blend door axleshaft when the actuator is removed. This will show you if the blend door is having a hard time grabbing the door due to broken bits… sometimes they are cracked and sometimes half the circle is just missing

I have fixed many many blends door issues from a 5 minute fix with a finishing nail, cutting the box open and installing a new Dorman door, to pulling the whole dash and replacing the box. 95-98 are bad, the later trucks 99-04 not nearly as many issues… could just be the age.

 

[greasepixels]

Yes they are physically the same door and hvac box
The actuator is the only thing that differs analog to digital climate controller

You can use a dental mirror or the camera on your phone to look down at the blend door axleshaft when the actuator is removed. This will show you if the blend door is having a hard time grabbing the door due to broken bits… sometimes they are cracked and sometimes half the circle is just missing

I have fixed many many blends door issues from a 5 minute fix with a finishing nail, cutting the box open and installing a new Dorman door, to pulling the whole dash and replacing the box. 95-98 are bad, the later trucks 99-04 not nearly as many issues… could just be the age.

Can you elaborate on the finishing nail's role in that fix? I'm debating cutting into my plenum and giving my blend door some persuasion...

My '95 has EATC, and I already replaced the gears in the actuator the last time I had the A/C working. I'm sure something is now physically up with the blend door, because it started flopping to one extreme or the other. In that case, is the actuator going to be unhappy if it can't do its sweep / calibration step successfully because I intentionally stuck the door in position to only allow flow through the evaporator?

To the OP, I love the ball valve idea. Will be chucking a spare one I have just before the HCV.

 

[98eddieExpo]

Can you elaborate on the finishing nail's role in that fix? I'm debating cutting into my plenum and giving my blend door some persuasion...

My '95 has EATC, and I already replaced the gears in the actuator the last time I had the A/C working. I'm sure something is now physically up with the blend door, because it started flopping to one extreme or the other. In that case, is the actuator going to be unhappy if it can't do its sweep / calibration step successfully because I intentionally stuck the door in position to only allow flow through the evaporator?

To the OP, I love the ball valve idea. Will be chucking a spare one I have just before the HCV.

The ball valve worked quite well actually. It's still not *quite* what it should be, but it does blow actually cool air now. A 1/2" threaded ball valve with two 1/2" MIP x 5/8" barb fittings is what I used.

 

[98eddieExpo]

Yes they are physically the same door and hvac box
The actuator is the only thing that differs analog to digital climate controller

You can use a dental mirror or the camera on your phone to look down at the blend door axleshaft when the actuator is removed. This will show you if the blend door is having a hard time grabbing the door due to broken bits… sometimes they are cracked and sometimes half the circle is just missing

I have fixed many many blends door issues from a 5 minute fix with a finishing nail, cutting the box open and installing a new Dorman door, to pulling the whole dash and replacing the box. 95-98 are bad, the later trucks 99-04 not nearly as many issues… could just be the age.

Huh, interesting. I wonder what exactly will be revealed as wrong with mine.

 

[410Fortune]

Okay well if your blend door axle is broken
Where the actuator square peg engages the top of the door, sometimes you can get the door moving again by heating up a finishing. Nail and putting it through the square peg
You leave 1/16” or so of nail sticking out each side and it can then grab the blend door and rotate it again… at least for a while

On my old 96 this repair worked for years
This was long before Dorman offered a replacement upgraded door

Blend door repair is tricky, if you cut your box open you must cut it properly and in the correct location to be able to drop the old door out, clean up and burrs or edges, install the new door and get it sitting in the hinge section of the hvac box
When you tape the box back together all edges must be smooth so the new door can swing without blockage

Three ways to repair a broken blend door, assuming the eatc controls and blend door actuator are in working g condition

Take a picture of your blend door, the top of the axle, where the square peg rides. Your phone camera can get in there and give you an idea if any of your door is still left. Usually they crack or half of the circle breaks out

This is when repair 1 comes into play
The finishing nail trick
By putting a little metal rod through the plastic square peg on the actuator, IN THE RIGHT LOCATION , you can force it to grab what’s left of your broken blend door axle and it will rotate again


Fix 2, if the door is too broken and there is no hope of getting it to swing again, get a good door from junkyard or dorman part
Cut box and install new door

Fix 3, the absolutely best repair, is to remove the whole dash and replace the whole hvac box. This is especially good if you have a leaking heater core and the dash has to come down anyways


When I crush 2001-2011 explorers and rangers I save the hvac boxes we we have the parts to fix the old 95-99 trucks which were really bad for this

I do all 3 of these methods often…

 

[greasepixels]

Where the actuator square peg engages the top of the door, sometimes you can get the door moving again by heating up a finishing. Nail and putting it through the square peg
You leave 1/16” or so of nail sticking out each side and it can then grab the blend door and rotate it again… at least for a while

In this case, I would want to orient that nail perpendicular to the axis of actuator rotation, correct? As in, horizontally through the drive peg?

Fix 2, if the door is too broken and there is no hope of getting it to swing again, get a good door from junkyard or dorman part
Cut box and install new door

This is likely my situation, but I'm glad I asked for more specifics because I was really about to just cut a flap out of the vertical side of the box, which is easily accessible from behind the glovebox. My thought was that if nothing else, I would be able to wedge the door to either extreme of its travel, setting it up for cooling or heating once per season.

That approach would definitely have drawbacks though:

1. I would lose one of the nicer aspects of having EATC - setting and maintaining a target temp would be impossible
2. When in the full-heat position, there would be no airflow through the evaporator at all, even when using defrost modes. So no dehumidification even though the compressor is cycling. Which would make clearing a foggy windshield much more difficult.

So the Dorman repair kit is the way to go here - specifically 902-221?
- with the metal piece (which drops in from the top, keyed to the axle of the blend door itself)

This looks easy enough to install from the bottom of the plenum.

What are all the extra bits which come with Dorman's 902-202 kit, though?

Fix 3, the absolutely best repair, is to remove the whole dash and replace the whole hvac box. This is especially good if you have a leaking heater core and the dash has to come down anyways

I will undoubtedly be pulling the rest of my dash at some future date, because I have been chasing parasitic drain issues and other annoying electrical gremlins for years. Being a Limited, my truck was packed with options, many of which have been disconnected and removed because they stopped working or I suspected they had something to do with flat out murdering a succession of batteries. I have left the harnesses intact, except in the case of soldering pigtails back onto the engine bay harness to at least get the OHV running properly, very early on.

But I still have so much detective work left to do with those issues.

Heater core isn't leaking (yet, at least) but it would be nice to remove any debris from around the evaporator.

I've really hijacked OP's thread. But he doesn't seem to mind too much I guess

 

[410Fortune]

They break like this

You would want the nail to go through the square peg in the corners like this (red line)