A/C charging issue resolved.

[Ed Lijewski]

Dean: "When I said - "My vent doors and motors are working fine. My whole A/C system is working as it should." that was before I pulled the vent deflectors off and had a look! Up to that point I could hear the doors operating, so I assumed they were good."

In a separate post ~2 years ago on my pics of failed vent door flaps and my removal of those vent door flaps I suggested you and Fresh Air Inspector take a look at the door flaps in your Scorpios. FAI did and as I recall noted that his were in poor condition also. You didn't in confidence that your door flaps couldn't be failed because it's a low mileage Oregon car (as if that had any relevance...) and you could gear the motors operating (also has no relevance to the doors material suffering fatigue). I never reported that my vent door motors weren't working and implied that the doors/flaps were in fact being twisted under working motors normal forces.

But, and here's the kicker, concerned about air flow in the system, you assumed "a" or "the" restriction in the vents would be the dash air vent deflectors, not the vent doors/flaps. So you set about designing and printing replacement deflectors. Wrong. Any marginal comparative air flow gain from those would be de minimis at best.

That was an error stemming from vanity, er, Vane-ity.

And the above is to assure the correct written history of our exchanges here.

Carry on your nice work on the door flaps my brother.

YMMV

[brokencase]

Ed, I take a slow, and systematic approach to these things. I also take a minimal risk approach. My first step was to address my driver's side vent which was jammed. After addressing this I might have left it with that as my other vent doors were functional, but upon close examination, not optimal. But success was achieved on the driver's side and easy to extend to the passenger's side. Now emboldened, I move to the center vents.

It is a bit scary, as one destroys the existing vents in the process of removing them. Success is not guaranteed.

When I'm done, and I am almost done with these vents, I believe I am going to have not only functional vent doors, but well improved vent doors, not to mention improved vent directors.

I believe I have, through my own, step by step discovery, along with some of your input, arrived at a very good solution. One that I hope I can share with others, as few as they may be.

Improved flow, Improved durability, quiet operation, easy to retrofit and upgrade, etc..,

I will post the 3d models and instruction on thingiverse.com for those who are so bold to venture into this game.
I will even post a video explaining my discoveries, how to remove the old vent doors, how to install my new doors, and my thought processes in designing the new doors.

Sadly, I cannot offer a solution for broken vent motor gears, as mine are all functional. However, if any of my motor gears break you can rest assured that I will provide a solution for this failure case as well.

As for long term reliability of my solution, only time will tell. But I have made them easy to replace so this allows for future improvements.

Possible improvements?

If the ABS plastic does not hold up and twists, I could then print them in something like Priline polycarbonate/carbon fiber filament.
This would require a different method of bonding the two halves.

If my 0.6mm polyurethane seal does not hold up, I can alter the model to accept a cutout foam seal like the original. But I see this as highly unlikely.

As it stands now, I have finished 3d printing the center vents and I will attempt to install them tomorrow. If all goes well I will make a video.
I feel pretty confident regarding the center vents, but you never know, I might have to make subsequent revisions.

Lipstick on a Pig? How could you say such a thing? Are you a true enthusiast, or not?
Ripping out the vents doors and proclaiming success? Heresy, I say.

[Ed Lijewski]

Pig, or little oinker, isn't far off.

Think of how many days/weeks/years you, I, and others sat in our Scorpios' drivers' seats watching macadam slide under our vehicles, hearing those vent motors actuate and then smiling with smugness on the technical excellence of the EATC, but totally unaware that vent airflow was majorly or minorly compromised by twisted or even failed vent doors in one or more vents.

We above were duped into pseudo bliss by unquestioning faith in an admirable EATC for its day with an airflow cabin design that didn't include vents near the upper lip of the dash as likely all other vehicles of it's time sported. The XR4Ti, starting point for the Granda/Scorpio, has them; so should have the Scorpio.

So, yes it's a pig, maybe a pet pig with all of its endearments, but a pig nonetheless.

YMMV

[brokencase]

You should be made aware that even with an improved design vent flap, you'll have to periodicaly visually check each vent's flap actual position for the selected EATC positions.

I observed that the OE flaps seldom stopped in "clean" full open (perfectly horizontal). That may have been a result of torqued material or motor gear wear. Ditto when the EATC setting involved a blend of air flow (footwell, center, defrost; different combinations of these).
YMMV

Ok Ed, As much as I hate to admit it, you have words of wisdom in your statements above.

I installed my center vents today, and I also observe "seldom stopped in "clean" full open (perfectly horizontal)" position.

When setting the panel setting on the EATC, the center vents move past the "clean" position and it is almost as if the airflow catches them from behind and they tip upward. I can push them down easily to the "clean position" with my finger and they will stay there.

What is going on here?

One possible solution I was considering is making some sort of hard stop that prevents the vents from overshooting the "clean" position.

Now I am starting to see why you pulled your doors out.

Maybe I'm heading for full vent door removal for the summer until I can figure this positioning thing out.

In all other aspects my new vent doors work well, they are easy to install and when I set floor or defrost the doors close nicely and the polyurethane seals close up nice and tight.

Vent doors aside I did install the bezel and one my improved flow vent deflectors on one of the center vents next to the stock deflector.
I can noticeably feel improved air flow with my hand coming out of my low restriction deflector, this case holds even if I swap their positions.
So my new deflectors get a thumbs up. I am going to start printing a full set of those with the angled directions I desire.

[brokencase]

After researching the IMON archives, I've come to the conclusion that I'm going to have to pull my vent motors and see how the gears look inside.
Particularly the center vent motor.

One archive post suggest unknowledgeable techs inserting temp probes into center vents as a probable cause for breakage of the center vent motor.

So what I'm going to do for the summer is operate in "Lijewski no door" mode. No problem, I'll set my new vent doors on the shelf until the fall.

For now, I'll install my hi flow vent deflectors and enjoy copious amounts of cool A/C air.

This is not defeat Ed, I will make my vent doors work.

Not to mention I will (hopefully) be able to provide a 3d model of the gear that breaks.

[Ed Lijewski]

Ba da baba da! (I'm lovin' it.)

Dean: "Vent doors aside I did install the bezel and one my improved flow vent deflectors on one of the center vents next to the stock deflector.
I can noticeably feel improved air flow with my hand coming out of my low restriction deflector, this case holds even if I swap their positions.
So my new deflectors get a thumbs up. I am going to start printing a full set of those with the angled directions I desire."

Your air flow observation is not a valid test of your Cool Hand Hedin vent deflectors. There could be a small source of friction in a vent air housing, or the plastic two channel hose from blower to center vent might not be sealed tightly all around the housing receiving mouth.

One archive post suggest unknowledgeable techs inserting temp probes into center vents as a probable cause for breakage of the center vent motor.

Wishful blaming by that poster.

From much experience it's clear that an a/c thermometer probe will insert easily in any vent as long as the EATC isn't in full Defrost or Footwell mode, and any touch-contact of the probe on a vent door will not move the door.

When setting the panel setting on the EATC, the center vents move past the "clean" position and it is almost as if the airflow catches them from behind and they tip upward. I can push them down easily to the "clean position" with my finger and they will stay there.

Solution: Drive with a finger ready to uh proctologically insert it in the troublesome uh opening.

FYI, new motor gears were/are available (from Merkur Depot). I bought and installed a replacement set on one vent motor. But the issue if the vent door not stopping in perfectly horizontal position still occured.

YMMV

[brokencase]

Nope, I am convinced with my improved flow deflectors. It was very clear and obvious to me. Much more air flow. Not to mention...quieter.
Besides, if you hold the original and the new design side by side the additional flow area is very clear.

I think that earlier poster was implying was that the A/C tech left the long thermometer probe inside the deflectors and into the door passages, so when the vehicle was turn off and then back on the doors cycled, and then hit the resistance of the probe.

Today I printed all four deflectors with a 20 degree deflection.

I also modified the 3d model for a blanking deflector, for the case if I need defrost. I am printing one of them now.
The change was about a minute and a few lines of OpenSCAD code to make the blanking deflector model from the previous model.
However it takes three hours to print the blanking version.

I thought about putting a "Merkur" logo on the blanking deflectors (see attached), then I thought, nope. That would be putting lipstick on a pig!

So, regarding the vent doors and associated motors you seem to proclaim there is no hope?

Ed, I swear to you on my mother's grave I shall make these vent doors work, and work properly. Even if it means additional circuitry.
When I select panel. They are going to be "knife edge" perfect.

I'll tell you what, with my new doors closed for defrost mode. The blast of air in the defrost vents is something I have never previously experienced in my ownership of two Scorpios! Which tells me even my earlier Scorpio from the 90's had vent door issues.

blank2.jpg

blank1.jpg

[Ed Lijewski]

If anyone might resolve the issues found so far I agree it could be you, particularly given your electrical/electronic expertise if the EATC's vent door calibration for powering the motors to "stop exactly horizontal position" has to be recalculated.

Vent motor door drive gear:

http://www.merkur.50megs.com/catalog_1.html

YMMV


.

[Ed Lijewski]

Dean:

So my new deflectors get a thumbs up. I am going to start printing a full set of those with the angled directions I desire.

And how do they look installed on the wooden veneer center vent panel?

YMMV

[brokencase]

Yes, I have that image saved previously. I can generate a passable a 3d model just from that image. But without a ruler next to it I don't know the scale, nor do I know the thickness So I will have to wait until I tear one of my motors apart.

But in the worst case...

I think you can agree that the desired position of the doors can be fully ascertained by the state of the three "DEF, PANEL, FLOOR" indicator lights on the EATC - Correct?

One could simply replace the door motors with some cheap stepper motors. Then have an Arduino board examine the state of the EATC LEDs and move the stepper motors accordingly.

[Ed Lijewski]

I think you can agree that the desired position of the doors can be fully ascertained by the state of the three "DEF, PANEL, FLOOR" indicator lights on the EATC - Correct?

Don't think so. From my observations the EATC considers data from IIRC 2 air temp sensors and in Panel setting will modulate vent doors to adjust individual positions for desired passenger cabin temperarure.

The Merlur Depot vent motor drive gear is made from a stronger than original material (can't recall what, but Mike at MD probably would know). Of course I understand your Vane-ity requires that you design/print a different one....

YMMV

[brokencase]

https://www.ebay.com/itm/225605302316

$20

Sample code to drive the stepper motors is here..
https://app.arduino.cc/sketches/0ef3a3d ... de=preview

[brokencase]

No, the blend door manages temperature.

From the EVTM book:
"The EATC Control Module stores the selected temperature and monitors the In-vehicle Discharge Air Temperature Sensors.
The module positions the Temperature Blend Door Motor so the correct amount of air conditioned air is combined with air from the heater core to provide the selected temperature."


The EVTM describes how the vent doors operate, and there are cases where it sets the panel side vents to 50%.
But in all honesty I'd be satisfied with basic open and closed operation for, PANEL, FLOOR, DEFROST operations.

Better software library here...
https://github.com/tyhenry/CheapStepper

...and more details about the motors
https://arduinoinfo.mywikis.net/wiki/SmallSteppers

"These motors/drivers are made by the millions for A/C units, fans, duct controls etc. which is why they are so inexpensive."

[brokencase]

Dean:

So my new deflectors get a thumbs up. I am going to start printing a full set of those with the angled directions I desire.

And how do they look installed on the wooden veneer center vent panel?

YMMV

I'll post a pic shortly.

[brokencase]

Vents in bezel:

flowvent.jpg

blockvent.jpg