I have a 74 XLT 390 with original A/C. I don't know if factory or dealer. It does not work and to make matters worse, its missing duck work under the dash. The heater core box is cracked plus other problems. I am considering removing everything and installing a new aftermarket set up. without heat! Granted, it could be a simple repair, but who knows. In your opinion, is any value lost or gained by doing this?

 

I ripped out all my stuff and went with the vintage air. However, with it now fall, I was not able to use the unit enough to give a solid review. It is definitely better than no A/C at all.

 

Aftermarket. You are opening a whole can of worms trying to make almost 40 year old stuff work or last. Rubber and plastics do not hold up that long. Look up nostalgic AC they have a complete kit that works for our style trucks. It’s comes out the same as vintage but it’s already tested and fitted. I am going to do that myself soon.

 

Tagging in for info. I have the High output heater system, and it's Forking HUGE!


May cause a problem with 7.3 fitment.

 

No fitment issues here
.

 

I already capped off the heater hoses at the intake and water pump, everything was so drafty that it always felt like the heat was on!
What can I expect to find if I remove the heater core box from the engine bay?

 

If it is factory installed air you will find a really big hole through the firewall.

Good luck

 

If authentic restoration is not among your objectives and you are willing and able to spend a bit more money than a rebuild would require, I'd argue for a whole new modern system with all new components. Modern stuff will work better, take less power and space. I am headed in that direction with my '76 F-150 having ripped out the factory air components, blocking the big hole created with an aluminum panel and investing in a Sanden compressor and new bracketry for my FE engine.
I haven't yet committed to an aftermarket supplier but I am leaning toward Vintage air because their dash controls don't require vacuum. You can get heat, AC and defrost with no increase in the size of the unit due to modern efficiencies in design. Of course, insulating the cab is key to any system working up to its potential.

 

When doing the removal, should I leave the original compressor mounting bracket and belt tensioner for the aftermarket set up, or do they provide there own brackets?

 

I know of at least two approaches to mounting a Sanden compressor on an FE engine:
1) Brackets that mount on top of the stock bracket (various vendors)
2) Brackets that completely replace the stock bracket (Vintage Air)

In either case, you'll eliminate the idler and bracket.

Browse Summit to see what they look like and why they don't need the idler.

AFAIK, there is only one kit that is specific to our trucks (Nostalgic Air) and that would come with compressor and brackets. With Vintage, we have to assemble our own components. They have kits for other vehicles but not our trucks. Still, that's not a big deal because the components are pretty generic by and large.

 

Did you remove the heater core box in the engine compartment and fabricate your own block off to cover the hole.?

 

I used the housing as a template to make an 0.50" aluminum block off plate that looked like this:



... until I painted it satin black later on.

 

My latest redneck idea on retro-fitting a non-OEM AC system is an early-to-mid '90s Corolla HVAC box. I'll have to remove one at the junk yard and see, but I think I can control the Corolla HVAC box with my Dent's original non-AC cable actuated controls. The Corolla uses no vacuum. I'm pretty sure the Ford fan switch will control a Toyota fan, which leaves a single On/Off switch to control the compressor clutch, and plumbing the vents. (I've thought about running AC air-output hoses back across the floor and up a C-pillar, and having literal overhead vents in the headliner!) I tried googling, and the box looks kind of big and square, rather than rectangular, but I've got the big factory AC hole in my firewall to work with. I would probably just put some vents under the dash which would blow up to face level...

My Hillbillyish way of thinking also stumbled acrosst the idea of simply replacing the heater core with an AC evaporator core, and using a toggle switch to control the compressor. But I think that would only work in a seriously warm climate where the heater is never needed. Plus you'd need to do some plumbing in order to hit your face with cold air...

After reading about how a heater box from a '71 Mustang is the same as a High Output heater in a dent, I've also wondered about a Fox Mustang HVAC box, but you'd need vacuum to control it - requiring an OEM Dent HVAC control, or maybe one from some other still-commonly-found Ford product.

 

THREE different types of A/C for 1973/79 F100/350 & 1978/79 Bronco:

1) Factory installed integral A/C is combined with the heater. The A/C controls are in the same panel as the heater controls.

The huge A/C evaporator case is located on the right rear corner of the engine compartment.

There is a vacuum controlled heater water valve spliced into the inlet to heater core heater hose, located at the right rear of the engine compartment.
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2) Deluxe dealer installed A/C is combined with the heater. The HUGE A/C bezel sweeps across the entire right side of the dash, covering up the glove box.

There is a separate 'hang-on' glove box bolted to the underside of the dash.
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3) Economy dealer installed A/C is not combined with the heater. The two A/C switches fit into a panel that also contains two registers.

This panel fits into the dash to the left of the glove box.