air conditioning

[Goose]

I can't seem to pull up any existing info on after market air conditioning systems for a '72 GMC. I'm looking for some help on which system to buy for my truck without factory air. I previously used an Old Air Products system with R-12, but now want to pull out the existing heater and install an after market a/c and heater combination. Anyone done that lately? Thanks.

[CST10]

I installed a vintage air system with heater in my 70 c10. Works great.

[schwoch1]

I used the Vintage Air setup in my '71 and was not 100% happy with it's performance. Vintage air said it was working as intended, but it never got REALLY cold. It would just start to get to about 45* duct temp and then it would kick out and kick back in at 55* and go down to 45*, always was cycling warm to cold. Heater worked OK, but again, I think it was a little undersized for the truck. It was a nice kit to install, it was very complete and thorough, just was not 100% impressed with the performance of the A/C compared to a factory style system!

[Goose]

Thanks. Did you have factory air to begin with? If not, did the sheet metal provided by Vintage fit ok? I appreciate the candid response on cooling. When it's 100+ degrees down here it has got to cool or why bother. Did you use Vintage Airs electronic control head or keep the cable system?

[schwoch1]

The truck was an original air condo truck, but there was not enough pieces of it left to make anything work, previous owner gutted all of it to make the truck 'go faster'!!!

I used their setup with the servo motors, I believe it was the Gen 4 system. Installation was a breeze and couldn't of asked for a more complete kit.

Vintage Air blamed the lack of performance on my compressor that I was using. I used the factory GM Non variable displacement truck compressor that came with my 5.3 that I put it in. They kept telling me that the compressor was variable displacement and told me I did not know what I was talking about (that wording exactly), after I explained to them my 20 years as an auto tech, my ASE master Cert, my EPA 609 certs and state of WI A/C certification, they relented a bit and said that the electronics were kicking the compressor out on evaporator undertemp and without using their aftermarket Sanden compressor, they would not be able to help with troubleshooting! The displacement of the two compressors was almost identical, so I feel that they were looking for a cop out to get me off their case!

I live in SE Wisconsin, and it gets muggy as hell here, and the system worked alright at pulling humidity out, but you had to run the A/C system WOT all the time to feel comfortably cool in the cab. If I had to compare it to the stock R12 system that was originally in the trucks, the Vintage Air setup did not perform as well! We had a '72 C30 with factory air condo and it would give you nip ons when you cranked it up, the vintage air setup would not do that!

I hate to bash their system, it was an excellent system to install and was very thorough, just the A/C system needs a little tweak IMO!!!

Sorry for the long rambling post, hope this helps!!!

Mike

[Goose]

Thanks again, that is exactly the type of information I need to help make an informed decision. Your credentials increase the value of the response considerably. I appreciate the help.

[67ChevyRedneck]

Originally Posted by schwoch1

I hate to bash their system, it was an excellent system to install and was very thorough, just the A/C system needs a little tweak IMO!!!

Sorry for the long rambling post, hope this helps!!!

Mike

Absolutely nothing wrong with Vintage Air if you buy it as a kit. I've had mine in my truck since 2006 and put thousands of miles on my truck in 90+ muggy SC summers. Blows Ice Cold. It doesn't matter if the compressors were "identical", if their system wasn't designed to work with it, it wasn't designed to work with it. A 305 is identical to a 350, but they are not the same.

The one in my truck performed so well I put another kit in my 65 Mustang last summer.

They both work so well, one will be going into my 67 firebird.

Click the link in my signature for an install.

[Lee H]

I installed VA several years ago and I'm happy. Even when it's 100+ I don't need run it on high. It stays about 40-42 out of the drivers side dash vent.

[Z10]

I put a VA system in my 72 this past winter and drove through some nice hot West Texas heat this summer. It works great. Check out my build thread for more info and photos.

[screaminchevypickup]

Can't go wrong with vintage air!! I've installed many and never had any problems.

[Goose]

Thanks guys for all the great reads and comments. Looks like some good options out there and none of them necessarily perfect. But then the truck is 42 years old and less than perfect to start with.

[davepl]

To the fellow that found it cycling out at 45F, rather than not working well perhaps it's working -too- well. I forget the exact number (not an AC tech) but even a 20 degree drop (not great) might be acceptable.

In your case perhaps there's a discharge air temperature sensor that kicks it out if the discharge air is too cold. I have a cellar in my house that's air conditioned and if I try to keep it too cold (like 50F for long term food storage) it'll kick out for that same reason.

I presume it's to prevent icing up the heat exchanger, but that's just a guess.

[Goose]

I am not an a/c expert, but the Haynes book on a/c says a normally operating system "...should provide 35 to 45 degrees from the dash vent nearest the evaporator, assuming an ambient temperature of about 85 degrees ....". This was a performance expectation on a factory R-12 system. Should we have the same expectation from a 134a system? Since 45 degrees is at the upper limit of "normal" at 85 ambient, I can see where one would expect to see lower than 45 deg vent temperatures on either a factory or aftermarket system(although 45 apparently is still normal). Thanks again for very informative comments.