A/C charging issue resolved.

[Ed Lijewski]

Yes, re defrost flow, I planned to rely on manually closing the panel vents, then opening them when defrosting isn't needed. It's a small effort, the reach to the passenger side vent panel is most of that. My calculus was any a/c air flow--and heating air flow-- improvement was and is worth it.

I never thought to look into an issue re motor vent driver chips. From.observation in 3 Scorpios it seemed to me the base problem was failing/failed vent door material, which wouldn't be surprising given the EATC system works them on each startup.

YMMV

[brokencase]

Basically, the vent motors have no positional feedback to the EATC. So the EATC does not know where the vents doors are at power up.

At power up the EATC drives them long enough to get them to a home position. If the door hits the end stop sooner than normal then they are relying on the motor to just stall for a short period of time.

There is nothing wrong with this approach if executed properly.

But, given your experience and the pictures you have shown previously, along with my observation of blown driver chips, it seems this strategy did not work out in the long haul. Not to mention prior post by others who have broken the gears inside the door motors.

Not sure how they screwed this up. Typically one would put a current limiting resistor at the output of the driver so that you would be driving the motor with the least amount of current to get the door to move and no more.

I 3d printed my first vent last night. Fits and articulates nicely. I added the little pull tab on the side that is useful to move the vent up and down, and I can pull it to remove the vent to flip it over to change the 20 degree direction.

I think I'll add another horizontal vane so that it will look more like the original vent. I'll post the model up on thingiverse when I'm done.
Granted this may not increase flow that much, but the model may be useful for someone who has a broken vent.

I think closing the vents will work for your defrost. However, In the process of examining these vents I notice that once you close them all the way it can be difficult to get them back open. I suggest you spray blade mechanisms with some silicone lube. Perhaps another approach would be a 3d printed polyurethane cover that would snap over the vents?

I am still very disappointed in the vent doors aerodynamic design. You would think it would be more like a throttle butterfly valve, instead it is a flap that barely gets out of the way. Even when it is "open" half the air passage is still obscured. In any case, I am still very reluctant to cut the vent doors out as you have done. I'll have to think about it some more. Did you just cut them out with the vent motors in place? Like with a Dremel or something?

[Ed Lijewski]

The failure was material fatigue; flap material trials probably showed no significant distortion for say 10-15 years worth of testings.

When I decided to remove them I used a needle nose pliers to grab an end and twist it out: if that didn't budge one, I grabbed it in the middle and pulled it out. The damn things had frustrated me for several years and couldn't be made to work like new while still in place especially while using a/c, so I elected to yank them out. Period.

This one survived in the best condition (don't remember why).

YMMV
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[Ed Lijewski]

This photo wouldn't load in post above.

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YMMV

[brokencase]

OK, so if one is careful they can be removed, possibly without breakage, through the vent cavities, without removing the motor mechanisms, by carefully prying the ends away from the motor's drive pinion.

And, if one is careful, the vent doors could be replaced if one so desired, albeit with some difficulty, some time later in the future.

Thanks for taking the pictures.

[brokencase]

OK I removed my driver's side door. My thought on this was since the vent was not cycling like the others I could pull the vent to see if the motor is malfunctioning or if it was the vent door that was stuck.

In addition I now have a relatively intact vent door that I can reverse engineer to see if I can do my previously proposed polyurethane 3d printed vent door.

[Ed Lijewski]

Since acquiring your current Scorpio have installed a new fan clutch?

YMMV

[brokencase]

Yes, I have a new fan clutch with less than 8k miles on it.

I am not convinced on your "hood venting" via removing the weather strip. Mainly because the condenser is first and foremost in front of the car.
Who cares where the air goes AFTER it passes over the condenser?

Also you claim my method of driving a cooling fan while the A/C pump is active is only worthwhile in slow traffic. I'll counter that such conditions ARE the critical time to cool the condenser. While the car is moving at significant speed there is little concern getting airflow through the condenser/radiator. In fact, if you always drove your Scorpio over 40 mph you could safely remove the engine fan and clutch entirely and the car would not overheat and the A/C would work fine.

You seem to think that there is some back up of air flow in the engine bay and I don't believe this is the case. It is entirely fine and there is plenty of room for the air to exit under the vehicle.

Finally, R134a is actually a more efficient refrigerant than R12. However to take advantage of this in an R12 conversion, one must take extra effort to cool the condenser (or fit a larger condenser). I believe I have addressed this by having an electric fan working on the condenser during A/C operation.

[brokencase]

I did not have time yesterday to work on this, but this morning I arrived at the following.

New vent door for driver's side. Instead of the original vent that had a foam gasket seal around the perimeter, this one will will have a 1mm thick polyurethane gasket seal.

The door itself will be probably printed in ABS.

The hope is to make the main body just flexible enough to ease installation.

new_door.jpg

[Ed Lijewski]

Ideally it should be designed to minimize air flow friction (the OE flap doesn't).

YMMV

[brokencase]

Exactly, This is thinner than the original blade and it has no support ribs or cutout sections.

[Ed Lijewski]

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).

Assuming your new flap material performs well initially, it might not over time. You won't be able to submit it to bench testing to prove its durability.

New motor gears are available, but would they be reliably durable? You'd have to accept the seller's attestation to that.

R&R-ing the motors is a PITA due to tight working space.

FWIW I installed new motor gears on at least one motor (maybe two) which had broken gears. After installing it (those) and operating the EATC I found that the system wasn't happy with the flap positions and quickly torqued a flap(s).

These facts and experiences contributed to my conclusion that for A/C purposes especially where fullest unrestricted vent air flow is non-negotiable eliminating entirely the vent flaps is the measure to take.

FYI, the ideal solution is to remo e all EATC components, replacing those with the full.manyal HVAC controls equipped on the Euro Granadas. That is what XRs came with it, and it's easy as pie to use and adjust and never fails

YMMV

[Ed Lijewski]

Re vent air flow noise, the solution is to replace the flexible air tubes with unridged ones. No amount if flap and vane rejiggering will make as much of a difference.

YMMV

[brokencase]

I'd like to pursue having fully functioning vent doors, hopefully improved upon.

My center and passenger side door vents are working, I will study the motion and position carefully in order to ascertain the proper indexing when I install the new 3d printed vent door on the driver's side.

If I have success with the driver's side I will proceed with the rest of the vent doors in similar fashion.

If I cannot get the driver's vent door working then I may do as you have done and I'll just pull all the vent doors out and leave them out. In this case I will 3d print covers to go over the vents to permit proper winter/wet day defrost and floor heating function.

BTW, a more efficient squirrel cage blower design is possible...but let's not get ahead of ourselves.

cagefan1.jpg

[Ed Lijewski]

I've read extensively on R22, R134a, Blends, and other alternative refrigerants.

As you 'might' trust Hagerty's publishing a review of R134a, FYI:

"Bottom line, R134a simply doesn’t cool as well as R12."

I could include comparison pressure/temp charts, but for now:

https://www.hagerty.com/media/maintenan ... d-the-law/

YMMV