So I've started work on my 1972 Comet. Engine overhaul is in process, gutting the interior is next, and after that body work, painting, and then interior work. BUT, I've noticed that it lacks air conditioning, which turns my future ride into an unbearably hot oven. I don't mind the lack of A/C in my 1980 Chevy truck, but this car seems absolutely horrible. Since it didn't come with A/C, how can I add appropriate parts to put in an A/C system, preferably without spending a fortune? Would it be possible to cobble together something from other vehicles, or maybe even parts from a window unit (or am I just dreaming?)
I see no way of doing it and NOT spending at least a small fortune. I would say the cheapest you could possibly do it would be $500...and that would be tough. Plan on at least $1000 for a system that will work and continue to work for many years.
Unfortuneatly there is nothing cheap about AC. The factory system is archaic and a lot of work to install. New under dash add on air is big money. Its costs to be cold.
To get an idea of what a first class system would cost check with http://www.classicautoair.com/ Their business is retro-fit AC systems in '70s and older vehicles. I got an "Under Hood Kit" from them to upgrade my factory system. You're starting with a non-AC car so it will be more complicated for you. Some guys REMOVE their factory AC systems. You might get lucky and find someone here to swap parts with. That would probably get you a non-working factory system that you can go to work on.
I've got the entire set up minus compressor, accumulator and engine bay lines that I will be removing from a 76 in the next couple of weeks. The system has been open for who knows how long so it may not be serviceable any longer. I don't know what type of expansion device these systems use or if they are even replaceable but do some research and PM me to let me know if you want anything.
That's a start for you. Where are you? If you want to pick them up in Raleigh, NC I have two York compressors you can have. Not worth shipping. One came off my '72 Mav 302. The other is a little different -- not sure what its off but might work or might have some parts, e.g., clutch, you need. Also have an evaporator but its not in great shape. Also not worth shipping. I have the underhood lines and expansion valve that appear to be serviceable. If you're not in a hurry, you can probably have those too. I'll keep them till my new system is set up. I had the dryer/accumulator refurbished so I need it. Not sure what you'll need for pulleys. I have PS so mine uses the 3-belt pulleys. With that setup, at least, the AC belt just drives the AC.
This is doable. I did it last year, and for well under $500. (Not counting the cost of my time, of course...) My whole story is here: http://mmb.maverick.to/showthread.php?t=56226 Basically, since you have a '72, you will want to get some of your interior parts from a '73 or older dash. (Unless you want to swap to a later glovebox dash.) You need at least the package tray, the two side vents and their associated plumbing from an early car. You can swap the entire dash if you're prepared for the possibility of removing the windshield, but if you decide not to do that the only thing you lose is the center vent. I just have the two side vents and they blow very strong with the center blocked off. Plenty adequate for me. The rest of your parts can come from any Maverick with factory AC. (You might happen upon dealer installed AC, with the controls in the center instead of on the left. I'd stay away from that because parts are hard to find.) Get the heater/AC controls and the vacuum lines, cables and wires connected to them. (Don't cut. Find where they terminate and pull the whole piece.) Get the heater/AC box from underneath the passenger side dash. This part's tricky. There are bolts on the firewall, under the dash, and above the kick panel. On the lower left of the box is a drain tube. Remove that carefully or you'll break it. (I did, and was able to repair it with fiberglass.) Get the defrost duct. It's not the same on a non-AC car. It's held in by tabs you'll have to bend back. Get any other ducting, including the center vent duct even if you don't end up using the center vent. Now, under the hood... The only difference between a V8 and an I6 car is the brackets for the compressor, and possibly the hoses. So it doesn't really matter what the donor car has for an engine, as long as you get the right bracket. You will very likely need new hoses, but get the old ones anyway. I had my hoses made at CarQuest for about $80. Get the compressor, the brackets, and get the 3-groove crank pulley off the front of the engine. Get the condenser so you'll know what to order when you replace it. (Replace it with a universal cross-flow unit, even if the donor car has a good one. They work much better and they're a good cheap upgrade. Mine came from eBay.) Same deal on the reciever/dryer. You'll want a new one, but get the old one for reference. Get the expansion valve. (This can come out with the HVAC box. New ones are available and you might as well get one. Mine came from Rockauto.) Get the heater control valve. (Again you'll probably be replacing that with a new part.) Tag and remove all vacuum hoses attached to the heater valve and the vacuum reserve cannister. (That cannister is probably a rusted mess. I got a suitable replacement from a Chevy Astro van, plastic ball type, and I put a check valve on it.) There's a vacuum hose going to the engine too. Disconnect the wire from the compressor. (Again you don't have to cut this; there is a plug.) Push in the rubber grommet where the vacuum lines and the compressor wire come out, and thread all that back through the firewall. Now, with all this out of the way, take a look at the firewall. There are two plugs where the heater hoses would normally go on a non-AC car. Get those. Remove and keep any other plugs you see covering any holes. Get a piece of poster board and a marker. Pull back the carpet and insulation, tape it up to the the inside of the firewall. Go under the hood and trace with your marker the location of every hole you see, including the ones you already have on your car. You'll be using those to orient the template you're making. Duplicate all those holes onto your car using an appropriate sized drill bit and hole saw. Don't forget the hole where the drain tube goes by the trans tunnel. Before installing, inspect and replace anything that doesn't look up to the task. Check all diaphragms on the various actuators on the box. Replace the heater core now whether it needs one or not, because it will be a real pain to do it later. Replace any worn-out foam you see. (There's a kit with most of this stuff sold for Mustangs.) Vacuum lines, heater control valve... (Use a later model plastic valve if you can't find a NOS metal one. Instructions are on this site.) Fiberglass any holes or cracks in the heater/AC box. Clean, sand and paint anything that needs it. Installation should be pretty straightforward after you did all that. Here are some tips... Some people replace the compressor with a Sanden type unit. This can be done for around $500 additional investment. Kits and brackets are on eBay and other sites. I decided to try the stock compressor first and it worked fine for me. Later on I went to an aluminum version of the stock compressor, (available new or junkyard) and saved a lot of weight. You can put a small "pusher" fan in front of the condenser and it will help a lot. Wire that up by using the compressor wire to trigger a relay; don't power the fan off the same circuit as the compressor. You will find that you'll start eating fuses. This is because your heater fuse is a 15a piece and you need a 30a one. Refrigerant... R12 is expensive. R134 isn't, but it isn't necessarily optimal in an older AC system. I used ES-12a because it's more efficient and takes less rotational force from the compressor, thus saving you a few hp. (Some people are scared of that stuff because it's allegedly flammable. I figured so is my gas tank, but you can make that decision yourself. I called their tech line and they've said there have been no reports of car fires caused by this stuff.) I used about 2 1/2 cans. Oil. Whatever refrigerant you choose, use ester oil. About 3oz per 1 can of refrigerant. The reason for using ester is it's compatible with R12 and R134, but more importantly it's compatible with both mineral and PAG oils, either of which may be lurking in small amounts somewhere in your AC parts. If you use the stock compressor, it has an external sump located on top under a hex plug. Fill that before you fill the system with refrigerant. I was going to write a tech article about all this but never got around to it. Looks like I just did! I'll post pics and add this to the tech section later...
this is great info! you pretty much wrote it already. I think adding the pictures would be awesome. great job
Thanks alot for the informative replies... Unfortunately I may be putting off the AC for a later date. I'm having the head checked for cracks, and unfortunately it looks like I may be buying a new head (final report on that next week). Did that with my truck, and the part was $400. So, I'm trying to decide whether to keep my I6 and just buy the part, or save up some money to drop in a V8 instead. Anyhow, I'll tuck your advice under my hat and keep it for the day when I need it!!!
Just heavily tint your windows and keep them rolled up. People will think you have A/C and they won't see you sweating...
Okay, it's officially a Tech Article now. Thanks, Lord-D for making me accidentally fulfill a promise I made over a year go....
So did you block off the front of the plenum when you installed it so all of the air would be forced out the side tubes to the package tray vents? I still plan to swap dashes, but I did decide to give cutting my current dash for the center vent a try for now, and it really turned out to be pretty easy. I traced the hole in my A/C dash onto a piece of cardboard (including the tabs the vent screws to) and measured the location of the hole carefully and marked it on the template. I cut out the template and taped it onto the front of my dash and traced the hole. I cut it out using reinforced cutting wheels on my Craftsman "Dremel". I had to trim it a few times before the vent would go in easily, then I drilled the holes for the screws. It is best to mark them, then remove the vent and drill, otherwise the bit just pushes the metal up and the bit walks. I noticed after the fact that the A/C dash has thread clips for the screws to thread into, but it holds fine without them. The only thing I really need to do now is figure out how to remove the diffusers from the vent so I can replace the felt that keeps them tight -- they always end up pointed all the way down within a few minutes. If anyone wants a copy of the template for the hole, let me know and I can send it to you.
Exactly. Interesting. I didn't consider doing that because I thought with the recessed lip in the hole on the AC dash not present, the vent would stick out. How does your look? Yeah... That felt... Ugh. I have the same problem on my side vents. I need to replace that. I'm able to get them to stay where I want them by pulling out on the fins a bit, but I'd rather do it right.
