Perhaps an awful idea.

BrianX128

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So on my 1985 6.9 in another older thread I had discussed with a couple of you guys about how there was a dealer installed under the dash ac system on my truck. Whenever the previous owner bought it from the original owner they really just used it to haul firewood and go hunting in the colder months and the thing was annoying and hit ankles and it got removed and lost.

So, now as the truck is mine and I'm not a fan of driving a vinyl seat truck to work in dress clothes to a hospital and being soaked in back sweat when I get to work I was considering fixing this somehow and I had what probably amounts to a idiotic idea.. but we'll see.

I may not use totally correct terminology here so correct me as needed. The condensor (thing in front of the radiator with hoses) is still attached and still has one hose from it to the compressor. Also the compressor is still in the truck and hooked up and spinning (but one end of it is unhooked). Ill upload a picture of this area here in a second.

What I don't have is the hose that would go from the other end of the condensor wherever it goes (I think into one port on the drier which I don't have, and the other end that goes from the drier around into the side of the compressor.

I also don't have the evaporator and my truck has this giant box that says high output unit where the hoses for the heater core go into.

So what I think I need is the hvac box area from another bullnose truck that had ac that has the evaporator and drier on it, and then just hoses to connect the drier to the compressor and condensor.

I also have a 1989 F150 with a straight six (Hank in sig) that has factory normal ac, and the truck only gets drove in winter as it's gonna hit 300k miles here soon and its eroding away in the rust belt. I want to say that I couldn't take the drier and evaporator off of it to use on the other truck because of how the heater core and everything are situated on my truck but I'm not sure..

I don't mind buying a new evaporator and drier and hoses if I have to, but the hvac box area is what makes me hesitant to buy anything.. Advice welcome
 

genscripter

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I say go for it. My '88 E250 AC didn't work when I first got it, and after a decent amount of time and parts, I got it running. AC isn't really that hard to do, if you get a Ford Service manual to aide in finding and labeling parts. They have really extensive diagrams of the AC system and how much oil to put in and other specs.

Some of my concerns.... if your compressor has had a port open for years, I bet that compressor is full of dust and grime. You might need to invest in a new pump. Also, on my '84, '88, and '94, they all had very similar AC systems, but they were all slightly different, so none of the parts (especially the hoses and their connectors) were reverse- or forward-compatible. So borrowing from other vehicles might be difficult. I think my '84 had an expansion valve, but the '88 had a combination of orafice tube and expansion valve apparatuses. So, keep that in mind.

Also, I wouldn't reuse an old drier. they are designed to soak up moisture, and just the fact that it's likely 30 years old and moving it to the other vehicle will expose it to more moisture than it's designed for. You should buy a new dryer.

Also, check the condition of the condensor... you might need to buy new as well. My original condensor worked ok when I fixed up my AC, but it was weak and didn't work very well, so my AC only worked when I was moving. When I did my engine swap, I pulled that old condensor and bought a new one, that worked extraordinarily better.

If you can't find replacement hoses, you could get some hoses custom made that a local hydraulic line place.

If the old unit used R-12, and you are trying to retrofit it for R134a, then you should try to flush the existing components, so that you don't have even more grime and gunk from the old unit. Also, whatever gunk that entered the compressor. They make a spray you can use to flush it out.
 

franklin2

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You can't get the FACTORY A/C box from another truck and bolt it into yours. On the early trucks like yours, the firewall was different on a A/C truck with some large holes that yours doesn't have. And the heater core was located in the cab behind the glovebox, not like yours which is under the hood.

That is why they had dealer installed systems and they where so different. To get yours going again, you will have to work with one of the aftermarket A/C companies and see what they can do. Since you have some missing underdash pieces, you might have to get one of those big coil units that hang under the dash like the old mustangs had in the 60's.
 

gnathv

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You can put factory air in it. I added factory air to my 81 bronco. Took it out of a pick up truck. You will have to cut your fire wall, not a big deal though. You will also need the entire dash to get the vents, ducts, harness, and controls. Really wasn’t that bad. After I removed the plenum that went through the fire wall, I cut out the fire wall so I had a template for my truck. Just make sure unit comes from same body style truck.
 

Thewespaul

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Yes it will work, I would make a cardboard cutout of the f150 ac holes on the firewall and just transfer it over to the 6.9.
 

FordGuy100

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I've been thinking about running a split AC setup. Essentially its an ac unit you take apart, split the condensor/evaporator, mount everything, run custom lines, etc. Higher duct vents, but much higher volume of airflow. I've been seeing guys do this on camper van conversions. I'd make sure to mount the evaporator part in something a bit nicer but thats me.


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snicklas

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Justin,

That reminds me of the unit that mounted to the ceiling/roof of a big truck years ago. Remember my neighbor having something like that on a late 70’s or early 80’s Mack R Model with a day cab...... big white box on the roof.....
 

Thewespaul

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There’s a setup like what you’re describing on this 91, I’ll try and grab a picture of it
 

FordGuy100

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Justin,

That reminds me of the unit that mounted to the ceiling/roof of a big truck years ago. Remember my neighbor having something like that on a late 70’s or early 80’s Mack R Model with a day cab...... big white box on the roof.....

Yeah, I've seen those too. A lot of van guys will mount those up top for camping.
 

franklin2

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Just remember guys, starting about 1987 or so Ford changed things and started making the A/C firewalls and the non-A/C firewall trucks the same. So on a little bit later truck it can be a bolt in, the later truck had it's heater core behind the glove box with A/C or non A/C.

If you guys think stripping the whole dash out, cutting huge holes in the firewall, and then putting another whole dash in place is easy, then you have more gumption than I have.

And those later non-A/C trucks can be a good source of parts if someone with a A/C truck wants to get rid of their A/C and that big coil thing sticking out in the engine bay. The later non-A/C plenum does not have this protrusion for the A/C coil, and sits nice and flat against the firewall. So if you have a 80-up A/C truck and want to get rid of the A/C, just find a 87-up non A/C truck and get the plenum off of it. Gives you a lot more room under the hood.
 

BrianX128

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Yeah, I'm not really sure what I want to do. I wouldn't mind if it was an under the dash unit, and I saw some of those under dash units you can get like this https://www.ebay.com/itm/12V-Car-Ai...ash=item1a46b3db7b:g:h-YAAOSw~JRaoOJz&vxp=mtr

I thought about trying one of those and buying a drier and hooking up the system and seeing what happens. My condensor is capped off the only thing that it turns out that isn't is my compressor but I could always buy a new one. I really don't want to mess with the dash. I'd need new hoses as well. I don't know.

I've had odd experience with ac. I've never dumped stop leak in, but I've taken 3 dead 0psi ford ac systems and put RedTek12A in them with some ester oil to swell the seals up to make sure it doesn't leak out and never pulled a vacuum or changed an orifice valve or anything and they are all colder then my factory ac in my car or my fiance's suv and none of them have ever needed a drop added. I even overfilled my 7.3 with too much oil / coolant when my fan clutch died, blew off the high pressure relief valve on my compressor, and just "released" the whole system by accident. The relief valve closed itself and I put 134A in it figuring the seals were swollen enough at this point since it worked for two years and it was fine.

Not saying my next ac experience won't show me I got lucky with my other 3, but just adding a little oil and filling the systems have always worked for me. None of those systems were ever "open" though so I'm considering just buying a kit that has all new parts like this:

https://www.ebay.com/itm/A-C-KIT-UN...ash=item3d409cc713:g:5z4AAOSwhgJZX9y8&vxp=mtr

But I feel like that compressor won't work, and that an IDI compressor won't have the right hose connections to make it work and I'll just have a mess and waste money.
 

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