Back on the junkyard A/C subject...

[tragic59]

Came across an 80's Suburban in a junkyard today that had what looked like it must be a dealer installed A/C system installed in the rear. Looked to be completely enclosed unit with about 4 vents and some semi-hoaky looking controls on the dash. There didn't appear to be any hoses, or other mechanical fixtures running to the unit. Obviously there were wires running from the switches.

What all would I need to grab with this?

And more to the point, how does it work? There's no visible connection to a compressor.

I'm pretty ignorant of A/C systems in general. Does anyone have a simple diagram or link to a site that could give me the basics of how they work?

Thanks.

[Kustm52]

stolen from the web...

Like your body, the air conditioning compressor is the heart of the AC system, and Freon is the blood. The compressor pumps Freon throughout the AC system, either the older type R12 which costs as much as gold it seems these days, or the new environmentally-friendly R134A Freon. This Freon is a gas and liquid combination that is compressed and circulated throughout the air conditioning system. The compressed Freon is pushed through the system under pressure and is passed through different sized metal and rubber hoses and a special valve called an expansion valve that cause the gas to expand and contract.

This expansion and contraction makes the Freon gas very cold. This cold gas makes its way via metal lines into the dash area of your vehicle to the evaporator core. This evaporator core is like a small radiator, except it has cold Freon circulating inside and not hot antifreeze. A small fan (the AC blower fan which you control from the control panel on the dash) sits in front of the evaporator core and blows air across this cold evaporator and then through the vents inside your vehicle.

The other objective of the air conditioning system is to remove the heat from inside the cab of the vehicle. This heat is removed by the Freon with the help of the AC condenser located at the front of the car (usually in front of the radiator). The Freon coming back from the evaporator carries the heat from the cab to the condenser via rubber and metal hoses. Just like your radiator, the condenser is lightweight aluminum with many internal winding coils. The Freon travels through these coils, and in between these coils are small slits or fins that the Freon is forced through. The condenser will have an electric cooling fan mounted in front or behind it to push or pull air through these fins to remove the heat from the Freon. Some vehicles still use the old fashioned fan blade driven by the engine to pull air across the radiator and the condenser.

[tragic59]

Thanks Kustm. So, there has to be some hoses from the rear A/C unit to the compressor on the motor then...

I didn't actually remove anything on the truck, so I could have easily missed the hoses. But the sure weren't obvious.

[Stevie G]

Not sure about the 'Burb, but on a Mini Van, they 'T' off with a valve at the firewall and run back along the frame. It's a short hose if there is one and then hardline from there.

[Flexicoker]

this shows how air conditioning works, might help.

http://home.howstuffworks.com/ac.htm

[Model A Vette]

I saw one of those units installed in a van. They are pretty much self contained as far as the part in the interior. The hookup is the same as a "normal" a/c unit as far as under the hood: compressor, hoses and the part in front of the radiator. Basically it is just a regular a/c unit mounted farther back in the truck. There are some units that are heat & cool just like a VintageAir system.

[38Chevy454]

Just like Model A vette said, it is essentially a self-contained unit, with the compressor and condenser up front. There has to be some lines connecting it to the front. I have heard of people using those units before, they have the evaporator, expansion valve, fan and the ducting all contained in the unit.