adding air conditioning

[wrangler]

I'm adding air to my non air 85 pick up, and I know that the cut outs are different, but is the blower opening the same on both?

[85MudMonster]

Yes. It should be.

[Captkaos]

It has been a while but if I remember correctly they are the same.  Heater hoses aren't though as you stated.

[wrangler]

I'm just getting ready to start tearing the truck down, but I cant figure out how to get my compressor wired in.  My wiring diagram shows that the dark green comes from the evap pressure control but is there another harness or set of wires that maybe I don't have or are they already on the truck, tied up somewhere?  Any help would be appreciated!

[wrangler]

I'm also wondering about the vacuum tank.  I've never seen one in a ac setup or even heard of one until I got this factory repair manual.  Is there a way around this or do I have to have one?

[Lt.Del]

There is only one wire going to the compressor--green.  Well, maybe a black one for negative ground.  You are right that the green wire on the Pressure switch on the drier/receiver is the same wire.  If pressure is too low, it kills the volts going to the compressor.

You could, theoritically, put 12 volts right on the green wire going to compressor and the compressor will run.  That way you can check the circuit and/or compressor.

You can bypass the switch to check for pressure or malfunction of the switch by getting a small wire and touching the two terminals inside the switch.  Doing this will bring 12 volts straight to the compressor and kicking it on.

On TBI the green wire goes through the ECU to kick up the rpms when the compressor kicks on.

[wrangler]

my wiring diagram shows a wire going to a fast Idle solenoid, is this located on the carb?

[VileZambonie]

Don't go by that picture literally. That picture above is not what these trucks came with. There is no receiver dryer. There is an accumulator on the outlet side of the evaporator and an orifice tube on the inlet side of the evaporator. No expansion valve because it's a CCOT system unless it's a rear A/C system like Suburban's had.

If your truck didn't have AC you won't have the fast idle solenoid. It basically just pushes up on the throttle a little bit when the AC is on. If you don't have one you can bolt one on if you are running a Q-jet carb. In the factory wiring it's a green wire

[ssgoodman]

i dont want to hijack this post but i just ripped out all the air conditioning stuff on my pickup today and was wondering if it was worth recycling or if anyone would buy any of it.  was thinking about tossing it in the dumpster but thought i would ask before i did that.

sutton
sorry for the hijack.

[Lt.Del]

To not confuse you, the evaporator looks identical to the drier in the diagram. Here it is...



These things have an orifice tube in the high side.  If instaling one, ensure you look at the arrow for the flow and don't install in backwards.

Vile is right.  The only expansion valves will be in suburban with rear A/C.  I replaced one in my sub a while back.

[wrangler]

i've got some sort of solenoid already on my carb.  It's off of a 80 camaro and it had air.  It's got an electrical connection on it.  Been looking at it for years and have no idea what it is. Hope it's what I think it is.

[VileZambonie]

To not confuse you, the evaporator looks identical to the drier in the diagram. Here it is...

I think you mean accumulator not evaporator....

If you have the solenoid then you're all set!

[wrangler]

Got everything installed except the compressor wiring, but I need to know what to seal the area around the heater hoses and "C" in the above picture.  Can I use silicone?  By the way thanks for all the help!

[VileZambonie]

Use Butyl tape.

Also to increase the efficiency of the AC system and to avoid the refrigerant absorbing the heat of the engine compartment you should insulate after the orifice tube to the evaporator.

[Lt.Del]

right, accumulator--the evaporator is in front of radiator. 
As far as peicing this thing together, do not use a used accumulator. Once exposed to the air, it is worthless.  A guy at auto zone tried to see me one with an open box.  I looked at it and the plastic threaded plugs were removed.  I gave it right back to him and said "no thanks". Of course he didn't understand.

That's why many stores will not sell (or warranty) a compressor without a new accumulator (and orifice sometimes).

Thanks for keeping me straight Vile.