G-body A/C thread

[Brick442]

I'm in the process of restoring the A/C in my Cutlass. Everything A/C related under the hood was removed and all wires cut at the firewall. I am in the process of trying to replace everything and figure out what wiring is needed, but can only find bits and pieces of info throughout the internet.

I wish there was a guide to getting A/C working again in these G-Bodies using a stock style compressor . . . maybe we can start a thread here.

Anyone have any A/C expertise they can add? What parts are required to get working A/C again?

 

[gs dewd]

Let me know exactly what info you need and what wiring your refering to and I will help you out the best I can. I do alot of auto a/c work and also have the 2 gbodies I own to gather info from.

 

[foxtrot]

You could easily re-wire the ac system starting at the climate controller. Just make sure to include the ac pressure switch and ac clutch relay.
Search on heater controls here at gbody forum dot com. I posted a link to some schems some time back. I think that they are located on mulibu racing dot com.

The mechanicals should be pretty staight forward. You'll need the ac compressor,brackets, condenser, dryer and lines...

I probably didn't help too much but it's a start.

One more thing -- The R12 system will need to be charged by a licen tech once u get it all back together. he will also leak check it... Good luck -- got to go, the kids are all over me to get of the computer....

 

[dan2286]

It used the computer from the factory, so if you do not have it, the factory wiring is going to have to be different.

 

[Blake442]

The only computer related function is the WOT cut-off switch on 442's and I think Turbo Buicks.
Other than that, the A/C system runs on a separate wiring harness, with no interaction from the computer.

 

[foxtrot]

I know that on the Olds 307 Regal model that the wiring did go through the computer.... The green wire from the AC switch did go to the computer to tell the computer that the AC is on. The brown wire from the AC compressor relay is controlled by the computer. The computer would basically disconnect the ground from the relay to turn the AC off if the freon got low. With all of that said I could not figure out why GM had the computer involved in all of this. Maybe just to log that the event happend? Never saw any trouble codes like that tho...

 

[Brick442]

Thanks for all of the replies!

The wire that plugs into the compressor . . . where does that wire come from? I have a bunch of wires coming from under the box where the blower is. Is the stock wire for the compressor a dark green?

Also, the blower is not working on HIGH. I replaced the blower relay and blower resistors, but have a black 4-pin plug with one heavy gauge red-wire and what looks like black, light green and dark green wires. I have no idea what this 4-pin connectors connects to (the other end must have been cut), but assume this has something to do with the current for the HIGH setting on the blower. There appears to be some wires on the cowl under the wiper motor that these may go to . . .

 

[82cutty]

Dont forget the vacumm lines to the a/c controls! I just got my A/C back up and running after my engine swap. R-12 is going to be expensive to get charged. I used it because I have the gauges and R-12 laying around. If it is all apart go ahead and spend the 75 bucks to get the retro fit kit from Auto Zone or other parts stores. If the A/C system is apart for a while you will need a reciever dryer and saftey measures replace the orfice tube. Most places will not charge it if the orfice tube has not been replaced. The you can rollup to Jiffy Lube type places and get it charged. As far as wiring, as far as I can remember the A/C stuff is on its own harness except for the green wire to the idle solienoid (sp). I seem to have either cut mine or hid it in some pretty loom. Hope this helps!

Steve

 

[Brick442]

Great info--I'll make sure I replace the old receiver dryer--and also have a new orifice tube. I know this can vary is some cars, where is the orifice tube usually on these G-Bodies?

Also, the heater valve. What is the function of it? And why is it inline on a monte carlo 305 and coming out of the intake on a olds 307? Does it make a difference where it is? I have a SBC.

Also, where is the vacuum hose that supposed to connect to it come from?

The pic below is basically what I am working with right now (I have the A/C lines that attach to the back of the compressor, just not hooked up in the photo). The condensor is not visable in the pic but the original one is there . . . car has something like 65K orig miles. A/C was removed in 1999 and the car was put in storage.

 

[82cutty]

The orfice tube is located right behind the dryer, there is a joint there. Seperate the 2 lines and it should be on the evaporater side of the line. I had to tug on mine to some out and it droke so I had to replace the evaporater. The dryer I got was a GM dryer thru Rock Auto for like 30 bucks. The heater valve will vary on engines with there placements, they control the heater core. When the vacumm is put to it it opens and the hot coolant will now run thru the heater core giving you heat. I have not had one on a car for over 15 yrs. but I dont drive mine in the dead of summer. If left off you may get some residue heat even if the blower is off. As fpr the vacumm line, I have 3. The black one goes from engine cacumm to the black vacumm resevoir, the pink and grey come off the resevoir to the a/c panel I believe. The grey one controls the duct work doors, if not hooked up the blower blows where it was last set(mine was defrost) the pink controls the hot or cold doors IIRC. I am not 100% on the vacumm lines but this what worked for my set up.