Aeronose A/C conversion

Has anyone done an A/C conversion from a aeronose on their bullnose? Im looking into using a 95 system on my 85 and was wondering if the whole system will work or not.

I don't know about 95 but i remember seeing on the FTE forum someone had taken the whole ac off a 94 and just dropped it in. Didn't even disrupt the gas in it. Trying to find the thread but am coming up short.
I'm considering it myself when my r12 system finally gives it up.

I converted Darth, the R134a condensor mounts differently than the old R12 one. if you can get the whole underhood system, the R134a evaporator is also larger. The inside has a better blend door that will close off the heater core completely in the full cold position. The end result even in a crew cab with a 460, it will freeze you out in the summer.

So i need a heater
box from a 92-96 to put its evaperator on?

BuggTruck wrote

I don't know about 95 but i remember seeing on the FTE forum someone had taken the whole ac off a 94 and just dropped it in.

I had no idea this was even possible, but maybe I'm misunderstanding...

You guys are talking about a conversion to put the 90's AC system in a Bullnose that had factory AC, correct? An AC to AC conversion?

This isn't so simple if the Bullnose (like mine) did not have AC, right?

subscribed from the "NorCal is 20 degrees hotter than it was 36 years ago" crowd.

No necessarily, it is just a better design, I think even the coffin nose (1987-91) is an improved design as far as the blend door. Everything bolts on the same way as long as the bullnose had either A/C or the factory dash vents so the ducts are there.

On Darth did you transplant the entire heater/AC box from a 92+ truck? And it bolted into the Bullnose dash? I get that you are saying it isn’t necessary but I’m wondering if it’s possible and if that is what you did.

I did, because I had a complete system from a 1996 F150 5.0L. I used the compressor and found a compressor set that would work, but later found a 7.5L set at Pick-n-Pull. It all bolts right in, biggest change as far as installing is the wiring harness changes.

On a Bullnose the front and dash harness are the same and to put it in simple terms, it starts at the right headlight and battery and ends at the left headlight. Coffin Nose models have a split harness, underhood and dash with a large round plug. Aeronose there are two rectangular plugs, a big one for the underhood harness (12A581) and a smaller one for the rear harness (14405). Dash harness is 14401.

With these, the A/C harness is a separate piece that comes through the top of the blower inlet housing along with the vacuum supply and recirc door vacuum. This is approximately where the Bullnose vacuum harness comes through. All the fastener locations are the same so no cutting or drilling was needed.

Good info, thank you. Were you able to keep the Bullnose HVAC controls or did you have to use the later one?

I changed the dash, steering column and brake pedal along with the parking brake pedal. I wanted to get rid of the crackhead wiring on mine. My dash was also cracked in several places, speaker grille (even though it was a factory stereo) had disintegrated.

If you use the same inside ducting the Bullnose controls will work fine, same functions. If you change to later inside ducts, as long as you keep a push-pull temperature cable (later ones are dual cable) then everything will work.

Gotcha. I am partial to the Bullnose interior, even if it isn’t as tight as the later ones... good to know it could still work.

MotorsportXLT wrote

So i need a heater box from a 92-96 to put its evaperator on?

It's more-specific than that, but yes.  The outside HVAC box must match the evaporator core, and there are at least 2 distinct cores/boxes:





And the hood latch support must match the condenser core (serial-flow R12, or parallel-flow R134a):



But the HVAC openings in the firewall didn't change from '80-96 (AFAIK)...

'82 -

'93 -

...so swapping any HVAC system among those years is relatively straightforward (as long as you get all the related parts).  For a while, I ran the original '83 underhood system with an '87 dash system & control.



Then I swapped a few underhood parts (with varying levels of success), and eventually swapped to a '93 body tub.  Now I'm using '95 underhood & '93 in the dash, but with the upgraded '95-97 temperature cable & control panel.  I'm not sure the '92-97 panel will fit the '80-86 dash.

Yes, the whole refrigerant system lifts out without losing any refrigerant, and very little coolant (if any).  I've swapped several systems on several trucks.  This one was blowing cold less than an hour after the guy pulled up in my driveway.

Sorry I havent been on for a few days... So if I grab the hvac box, and the complete a/c system off of a 95 ford bronco, everything will mount up in my 85 ? And I can use the 85 hvac controls for the system, but I can not use my 85 broncos original A/C wiring harness and plug ins to run the 95 A/C system?

MotorsportXLT wrote

So if I grab the hvac box...

The OUTside HVAC box, with the blower motor & evaporator.

MotorsportXLT wrote

...and the complete a/c system off of a 95 ford bronco...

Off any '94-96 Bronco or F-series (& '97 >8500GVWR).  For the compressor to bolt up, the donor must have the same shape engine (I6, or smallblock V8) as yours.

MotorsportXLT wrote

...everything will mount up in my 85 ?

If you also swap the hood latch support.  You should also grab the 2 rubber flaps between the grill & core support, and probably the one from the core support to the bumper.

MotorsportXLT wrote

And I can use the 85 hvac controls for the system...

Yes, although the '87-early '88 controls & inside box are slightly better, but NOT necessary and a LOT more work to install (the whole dash has to come out).

MotorsportXLT wrote

...but I can not use my 85 broncos original A/C wiring harness and plug ins to run the 95 A/C system?

I think you might need to change 1 connector &/or add 1 wire near the accumulator.  But generally: yes, the old wiring will work.

Steve83, FWIW, I did the A/C system swap on my 1986, but I had already changed the front sheet metal to 1990 for two reasons, first the PO parked by feel and both front fenders were damaged to a degree, second, I was doing an EFI conversion and the 1990 was the donor vehicle. I was already running an R134a conversion on the 1986 system which worked well other than the hot restart, at which time it would take a bit for the air to get cold. Gary Lewis has documented the blend door's lack of complete sealing of the heater core, that coupled with the uninsulated evaporator case was the most likely cause.

When I was doing the EFI conversion, I had obtained a complete system, less condensor and 460 hoses from a 1996 F150 that had been flown in the inverted position. I ordered a new 1994-97 condensor from LKQ along with an accumulator and red orifice tube. I found a compressor hose set for a 351 at Pick-n-Pull which worked, but was a little tight across the upper plenum. I later found a set on a 1994-97 crew cab at Pick-n-Pull that someone had tried to drop a 1988-89 460 into. I did score the oil cooler adapter and hoses though.

I was able to mount the 1994-97 condensor to the 1990 radiator support with some small modifications and the end result is a system that will freeze you even in our coastal Eastern VA area where the temperature and humidity race each other (temperature will win some days).

One item I found in doing this, there are two different compressor clutch assemblies for the 460, one is the same as the 302, which is the one on mine, the other is larger to lower the compressor speed. Since Darth has the 3.55 gear and now the E4OD I am turning 1500 rpm @ 55 mph and rarely see over 2000 rpm on the highway, accelerating, my EEC-V program is set for a max upshift rpm of 4500 due to a somewhat loose engine (had crap in the oil pump and did some lower end damage), when I install the new engine I will raise this to probably 6000 rpm.

Thank you for all the feedback! I will be doing this conversion in the spring, so I will probably be posting some more questions.