Some help please, I would like to add a/c to my truck, 81 F100 inline6 4.9, I would like to use a factory HVAC control I got from a donor truck, so

what will be easier, get parts of donor trucks?, if so which trucks are compatiable?, as far as mounting brackets and other necessary parts,

what aftermarket kits are out there that will allow for me to use the factory HVAC control?

I dont want add any ***** to the dash or bezel,would like to keep it factory look.

Thanx

 

If you want it to look and function like the factory system, you will need a donor truck.

People have their different opinions as to what constitutes a "major" job, but in my book, changing your truck to factory A/C will be a major job. The heating system is different and needs to be totally swapped out, along with all the ductwork. You will also probably need different pulleys and brackets for the front of the engine to mount the compressor.

 

I've literally just finished pulling the A/C box, dash, heater box in core, and associated ducting out of an '85. It was a major job getting it all out, and it was facilitated by removing the fenders.

It is a big job. BIG!

 

Your best, easiest, and cheapest way is to buy a new Vintage Air unit..Then it's all new components..and easiest to install...OR..find an aftermarket...under the dash unit...freom the 60s-70s like Sears, Wards, etc. I put one in a '66 truck with a 352..easy if you have ALL the parts...but keep in mind..it's all used equipment. A good rod shop could make the Vintage Air work on factory controls...

 

This is why the dealer had their special A/C kits. Huge Job...

If you can find a Dealer Deluxe A/C unit, if you want it to be Ford. They had the HVAC panel where your heater panel is. Make sure it's for the 300-6 engine.

The Years of Compatability for the control panels, 1980-1982, 1983-1986. It also depended if the truck had dual tanks or not. This is also not taking into account for engine differences. Some had different panels and cables for different engines.

Good Luck with what you decide.

 

I use to own an 81 with factory air so they are out there. But I agree with all here that it's a huge job and only if your willing to spend some time with your truck down. I've never dealt with an aftermarket unit so you need to rely on the others comments for that.

 

I asked about doing this exact thing once and decided it would have been more work than I was willing to undertake at the time (replacing the wiring harness came first) as described by this guy's response:

https://www.ford-trucks.com/forums/7...ml#post6297296

 

He knows whereof he speaks. As said, I finished today getting the dash, ducting, and heater box out of the cab on this parts truck. What I didn't say is that I also got the main wiring harness out intact. Boy, was that a job! Not only does it come into the cab on the drivers side and exit the cab on the passenger's side, it wraps around everything in the cab like a grapevine in a tree. There is no way I could put it back like it was w/o another truck sitting there to look at or a bunch of pictures - bunches. If swapping the main wiring harness was involved I'd find a different way.

 

Thanx guys for all the info..

 

Actually, no, it's not.

I was all excited to be finding a perfect wiring harness for my year of truck! Most of 'em have been hacked but this one was perfect!

Removing it from the donor took the entire Saturday morning in the junk yard.

After I got home, it THEN occurred to me, what about also getting the air conditioning? How hard is that?

So I asked here, and 8 Lugs responded.

Given what it took to get the harness (and that action taught me what it'd take to install it in my own truck) I figured, "Nah, maybe later."


Air conditioning is just an add-on harness to the main electrical harness, it's actually real easy. There are two thick wires that are connected together in non-AC trucks, you disconnect them and attach them to equally thick wires on the AC harness.

There's a small pigtail-like harness that fits into the HVAC controls used with AC, and the entire assembly is wrapped together and exits the cab on the passenger side in a hole just next to where the main harness protrudes through.

There is a different heater fan resistor to go into the different heater core box, a wire that runs to the compressor, and another wire that runs to the accumulator or dryer or whatever that cylindrical thing is called.



Point being, adding AC to a non-AC equipped truck is pretty dang easy from an electrical standpoint, it's just an add-on harness that gets plugged in.

I'm talking 1980-81, I believe 82+ are slightly different (might be 1983+).


I got a donor cab sometime last winter, it was a 1985 but it had AC. I'm kinda wishing now that I'd taken the stuff behind the dash and the heater core box, making it work in my 1981 I can't imagine would be too awful difficult.

But, I didn't.

 

I did this very same thing a few years back on my 81 F100. I had found an 86 F150 at a junk yard that they had just taken in and no one had touched yet. The guy told me be there first thing in the morning and I could get anything I wanted off the truck. I was able to pull everything I needed. I got every screw, bolt, bracket, hose, wiring, control panel, duct work, heater A/C box, and anything associated with it even the whole dash so I would have the passenger side A/C outlets. My truck did not have power steering or brakes so I got all that while I was able to get it. It would be best if you could find a working system in a truck to remove it from if possible these days. Like mentioned above I did not have to change the main harness out as the A/C is a separate harness and just plugs in. If I recall I did have to cut some of the firewall out for the new A/C box versus just having the heater box. When I buy any parts for the A/C system I just tell them it is an 86 so if there is any difference in the 81 it will cut down on having the wrong part.
Forgot to mention I did also replace the core support and the radiator from the 86 as they where different also on A/C equipped vehicles.

 

I sit corrected on the main wiring harness needing to be changed out - I misread another post. And, that's good since changing the main harness would be a lot of work, although adding A/C is still lots of work.

As for mod'ing the firewall, here's a shot of the firewall on the '85 I'm stripping:

Note that the passenger's fender is off, which greatly helped reaching the bolts on the far right side of the HVAC box.

 

I've done it and thought it was time consuming, but not a particularly diffcult job. But my tolerance for difficulty may be different than other folks. I swapped the dash out as a whole unit with the harness still connected so beyond disconnecting the harness ends, it was really pretty easy. The dash itself wasn't all that tough. When removing the dash as a unit there were only a few easily accessible bolts that actually hold it in...lower corners, upper corners, speaker support, and lower center support. Beyond the wiring harness, you just need to lower the steering column and disconnect the heater box. After the dash is out the vents are simple. Marking and cutting the firewall was the hardest part of the job, but that was made a bit simpler by making a cardboard template. I did remove the passenger side fender to do the job. I also had to open up the core support for a larger radiator and condensor. The whole job took a little less than two days. My truck at that time was an 82 and I used an 86 Bronco dash, so there were some changes to the harness end connectors that needed to be made, most notably for the clock and the fuel gauge to work, but again, they were easy and obvious.

 

You don't need to change the wiring harness when you remove the dash structure and it's pretty simple (Simple being a relative word depending on skill level) to cut loose and reattach the main harness to the dash structure. It's held on with clips and wire straps.

Cutting the firewall is indeed the most difficult, and beyond most laymen.

A Dealer kit would eliminate most of this swapping and cutting, although the instrument cluster bezel and the dash needs to be cut for the dealer air registers. Dealer kits do look added on though, but they are Ford parts.

 

I have dealer air in my truck. The only way you can tell is that the controls are 2 ***** located in the cubby space to the right of the steering column.