AC Stock or Aftermarket
 

So my 85 dually has factory air. It is missing the compressor and I am sure some misc parts.

All my squares have never had factory air. Is it worth fixing and getting to work or should I just pull all the old stuff out and put in vintage air or another aftermarket setup?

I would guess I would have a few hundred in fixing the old stuff vs $$$ for new. Cost difference is quite large.

Re: AC Stock or Aftermarket
 

It would be easier from where you are at to fix the factory stuff. Unless the under dash items are gutted for some reason.

Times not to use the factory set up.

1. You do not have it. At this point aftermarket is easier, and more cost effective.

2. You want it hidden. Alot if aftermarket systems can be hidden quite well compared to the factory unit.

Re: AC Stock or Aftermarket
 

The underdash stuff looks like its there, at least the heater box and controls are intact. I think its missing some of the tubing that runs to the vents.

Will the performance of the stock AC actually be acceptable? Its a regular cab so its not that big of a space, I just want to make sure it will actually cool before I sink a bunch of money into it.

Re: AC Stock or Aftermarket
 

They at this point will work as well as your inclined to restore or fix it.

Tubing gets loose, blending doors don't seal as nicely, and the fan gets old. Along with the resistor going weak. All lead to reduced performance.

I had a crew cab dually for 3 glorious weeks, and it's ac blowed cold. Even my notoriously fussy ex-wife was fine it on a drive to Riverside to pick a couch up for a friend of hers. In summer on a 100* day.

On a regular cab it won't be nearly as bad as your cab is 1/2 the size. If you do a conversion which honestly is the right way now. Do your research as R12 is different then R134. So the evap usually is good, but the condenser needs to be upgraded. Along with a new metering device.

So if I were you. I would pull the system apart and wash the Evan coil. Then clean out the box the bast you can from the engine side. Then decide if you need a new motor or resistor.

Re: AC Stock or Aftermarket
 

I highly recommend using the factory equipment. I installed a aftermarket unit and it worked fine, but didnt cool or blow the amount of air my 1986 silverado did.

Re: AC Stock or Aftermarket
 

I struggled with the same decision for a long time. I am doing a no expense spared build on a 1972 blazer, 2 Wheel Drive. I would really have liked to clean up the firewall. I decided to stay with the original heater and evaporator box. I am using a new Sanden compressor and new condenser.

There are a couple of things that swayed my decision. All of the replacement AC systems do not use outside air and block off the passenger fresh air vent. Some have said this affects the defrost function some. The other thing that helped me decide to stay with the original evaporator box was the size of the evaporator. The factory evaporator is almost the size of the entire unit that goes under the dash with the replacement units. This might not be as much of a concern in a standard cab pick up truck or a car. The interior of a blazer is much bigger and more difficult to heat and cool.

Re: AC Stock or Aftermarket
 

The stock AC system can turn the cab into a refrigerator.
The Harrison R4 compressor had poor longevity at best and the rebuilds are even worse. I would look into installing a Sanden SD5H14 / 508 or a SD7H15 / 709 compressor kit in place of the Harrison R4 pancake compressor.
If you have one of the earlier trucks with the Harrison A6 you can generally use them and still can get decent rebuilds. The Sanden compressors use noticeably less fuel and work just as well.
You will need to flush the bugs and dirt and other crud out of the evaporator and pressure test it.
The accumulator/dryer needs to be replaced any time you crack a system open. Use the old unit as a dummy part to build up your hoses. Break the seals and install the new one when you're ready to finally close up and vacuum the system down.
You might or might not be able to douche out the condenser. New parallel flow condensers are fairly inexpensive.

If any hard parts that were used with R12 are still present I would use Ester oil rather than PAG. I would also make sure the oil has UV dye.

Re: AC Stock or Aftermarket
 

The general consensus on the facebook groups is that the factory AC system easily outperforms the Vintage Air system.

Re: AC Stock or Aftermarket
 

well this isnt how I thought the suggestions would be haha. Glad to hear the factory stuff is sufficient. I will have to take inventory of whats still on the truck and whats missing.

Re: AC Stock or Aftermarket
 

I'm surprised too. Generally people seem to be happy with vintage air and the like. They seem to feel like that system moves a lot more air. I just don't like how it takes away the space in the glove box and also doesn't seem to provide good defrost. I don't mind the clunky old nature of the factory underhood pieces. They might not be beautiful, but they are original. There are worthwhile upgrades from what I understand - like a sanden compressor and there is some component, actually I think that Ford manufactures, that people say is an upgrade. Can't remember what it is, so a detailed search might be worth your while.

Re: AC Stock or Aftermarket
 

My truck never had factory air but I am very happy with the Vintage Air.

Re: AC Stock or Aftermarket
 

The Ford piece is the variable orifice valve.
If you're going to run R134a I would replace the fixed orifice valve with the Ford part.

That only appliex to the CCOT systems starting in 79 80 or 81 (I'm not positive on the exact year). The earlier systems have a Thermal Expansion Valve on the evaporator or accumulator fitting that's pretty hard to miss.

Re: AC Stock or Aftermarket
 

I ran Vintage Air in my Chevelle and am currently running the factory AC in my square. It blows just as cold, if not colder than Vintage Air. I'd save those pretty pennies and put them into something else. My 2 cents.

Re: AC Stock or Aftermarket
 

There you go. I thought I remembered that it sounded awkward. Glad that I got somebody else to say it, haha. Thanks hatzie ; )

Re: AC Stock or Aftermarket
 

It's sometimes called a Smart VOV.
This is a rather long winded discussion on the AC boards of the pros and cons of using one.
https://www.autoacforum.com/messagev...threadid=13106