Greetings All,

With several recent air conditioning questions on the forum, I thought this might be a good time to start a thread to document performance. I'd like to establish a baseline for what is possible. I'm especially interested in refrigerant retrofits since R12 is nearly unobtainable to us mere mortals. R134a often gets a bad rap but that hasn't been my experience.

Here are some suggested parameters off the top of my head. Please feel free to add more if you think of any. In no particular order:

1) Factory system or aftermarket? (Please state brand if aftermarket)

2) Refrigerant used? I'm running R134a, converted about 15 years ago.

3) If converted from R12, how did you measure the replacement refrigerant? I filled by weight, at 80% of the original charge.

4) Stock or aftermarket orifice tube? I'm running a 4 Seasons orange tube.

5) Cab size? This changes the volume that needs to be cooled. I've got a SuperCab.

6) Tinted windows? Not on my truck.

7) Duct temp at the center register at freeway speeds, let's say on a sunny 90 degree day. Fresh air, no recirc. At least 15 minutes into a trip. Mine measures 38 degrees.

8) Same duct reading in stop and go traffic. Mine measures 45 degrees.

9) Any other mods to the system? I've added a vacuum-operated heater line shutoff valve (Highly recommended!). I've also added some ThermoTec adhesive blanket to the evaporator case and the receiver/drier. The clutch cycling switch was adjusted slightly to work with R134a.

10) Last but not least, who'd win in a fight: A taco or a grilled cheese sandwich?

I've got my lab coat on and clipboard in hand, all in the name of science.

 

 

OMG, Too funny, My stomach is hurting!

-Enjoy
fh : )_~

 

Funny! But, on to A/C questions. Where did you pick up the vacuum for the heater line shutoff? I intend to do that, but hadn't decided how.

Otherwise, I'm here to observe.

 

What was the stock color for yours and what others may have?
I think I have also seen variable type or auto adjusting has anyone used this type?
I have also seen for severe climates(105+) anyone use this over the auto one?


Also what compressor are you using as I wonder if that would make a difference or not?


Did you change the drier/filter when the system was changed as this could also make a difference.


I would be real happy with the temps you have out of the vents if it was mine.
Dave ----
edit: is that grilled cheese sandwich with or with out bacon?

 

I put a tee in the line to the "panel door vacuum motor", as seen on page 82 here:


Heating, Ventilation, & Air Conditioning - ???Gary's Garagemahal



Vacuum is present when in Vent, Max AC, and Norm AC.


I'm running a BK6601294 shutoff valve from NAPA. I think it's for a Ranger pickup, IIRC.

 

Perfect! Thanks.

 

Sometimes on a damp day that is not very hot, you will want to run the system in A/C and add a little heat to it also. If you want to add a water valve and still be able to add heat, you can tee into the line under the hood over near the pass side hood hinge. Over there on my 89 is the actuator for the inside/outside air and it activates in "Max A/C" only. So it will cut the water off in "max" mode, but not in "Normal" or "vent".

I can't remember but I am assuming the 86-dwn trucks had that inside outside air actuator over there also.

 

Dave - Yes, the 80 - 86's have the inside/outside door there as well. And, I like that idea for both reason you stated as for the fact that the vacuum is already right there by where the shutoff valve will go.

 

Dave,


I'm super happy with those duct temps.


I've got the stock style FS6 compressor. I replaced the original about 5 years ago. It's the style that looks like this. This is a generic pic and may not be the exact one:









I don't remember the color of the original orifice tube.


No idea on the variable orifice tubes. I considered them, but thought they had more potential for something to go wrong, so went with the simple fixed one.


I also replaced the receiver/drier when I replaced the compressor.


I'm also a big stickler for a deep drawdown when doing the evac. Supposedly 30 minutes is plenty, but I like to draw a vacuum overnight whenever possible. Can't say for sure that it helps, but it certainly doesn't seem to hurt.

 

KR98664, thanks for the feed back on the parts you used.


When it comes time to get my system back together, been open for at least 8 months, I will also get a new drier because of age and open this long.


Also thinking of the severe climates (auto adjust) but may rethink that but all I see is blue thru AZ. I don't remember what color it has now when I pulled it apart.


I also have the York (big square unit) compressor just don't know if that would make a difference or not? Guess I could swap it but was told AC worked when the truck was rolled on its roof. Don't really have the money for a new compressor at this time.


Would be nice to see what others have done.
Dave ----

 

Dave,

This thread has the Four Seasons part numbers for the different orifice tubes:

https://www.ford-trucks.com/forums/8...a-c-motor.html

I know NAPA has them. That's where i got mine. They can search by the Four Seasons number. I'm sure you could also find them online. I bet Amazon has them.

 

Yes, my '84 has that actuator located just as you described. I didn't tap into that line, however, as I wanted the heater core off for Vent and Norm AC, too. One drawback to my method was I had to route a new vacuum line through the firewall. I followed the antenna cable. Not a showstopper, but access was a little tight under the cowl.

In the vent position, I've noticed the heater shutoff drops the temp about 15 degrees. Could be a plenum door not sealing off 100%, but I'm too lazy to tear everything apart to find out. Shutting off the coolant flow works for me, so I'm happy.

Back to running the AC on a cold day and adding a little heat, I just run the defrost for that. Not quite as good, but thoroughly adequate. The best of both worlds would be a manual (cable) control of the heater shutoff, or a manually controlled vacuum switch to override the auto function from where I teed into that one vacuum line. But I'm happy with what I've got so will leave it there.

I will say the AC does such a good job of cooling, I have to periodically switch it off for a few miunutes on long trips. With the heater shutoff valve automatically closed, there's no option to bump the hot/cold lever to the right for less cooling. That's my (chilly) cross to bear...

 

My plan is to use connection #1 on the HVAC control, which isn't used. As shown below it provides vacuum on both Vent and Max, but not on Norm. The plastic on the control isn't drilled, and there's no hose on that port of the connector, but I think that should be easy to fix.

 

Is there a way to let in a little of hotter outside air with the fan on low to get it warmer?
I ask because I thought the water valve is closed on MAX AC but you can still work the recirc air.


Wait that is wrong right? On MAX AC the recirc is set for inside air and the water valve you installed in closed also, so if you turn off MAX AC can you then use outside air?
Dave ----