1979 El Camino/ Have an AC question/

[mando13]

Hello everyone here at the forum.This is my first post here.My name is mando.I have a question about my ac.
I bought this truck 6 months ago and have been working on it ever since.I have it looking pretty nice now (compared) to what it looked before.The previous owner had removed the compressor,the condenser,the hoses,and the wiring to the compressor.The only thing left was the accumulator.
I replaced everything,including the accumulator.I am now trying to figure out the wiring to the compressor.The old accumulator did not have a low pressure cut-off switch on its side.So,there is where I am stuck.
Did the Gbodys have a low pressure switch mounted somewhere other than on the accumulator? I need to figure out how to wire the system so that I can have my friend evacuate and recharge the system.
Is anyone here familiar with this ac system and can tell me what wires go where?Or, maybe a diagram of the ac system.Also,I did Not replace the evaporator so is there a way that I can clean or flush out the accumulator?
Thanks for all your help.
Mando13

 

[Texas82GP]

I'm not an expert on the wiring aspect of your question but I believe earlier models of g-bodys didn't have the clutch cycling switch on the accumulator. I am under the impression they can be converted to having the switch on the accumulator without too much difficulty. Hopefully others will chime in.

As far as flushing the evaporator, I have flushed them while removed from the car with denatured alcohol and a siphon gun on my air hose. I also just partially fill the core with the denatured alcohol and slosh it around. I've had good luck doing it that way. On my car though, since I'm going to open up the top to the heater/ac case anyway I'm just going to go back with a new evaporator. Other than that, I don't think you can flush it except with the professional grade flushing equipment. Hope this helps. Welcome to the site by the way, from Houston.

 

[mando13]

Thanks for your reply Texas82GP. I appreciate your suggestions and help.You are correct in saying that the clutch cycling switch was not on the accumulator back than.I just found out that this el camino uses a Thermostatic cycling switch and is mounted on the outside body of the evaporator.I found it. But,instead of using that older switch,I am going to install a new clutch cycling switch on the accumulator.I will take the wires off the old switch and connect them to the new pressure switch.I did find a diagram that shows how this wires are connected.They start at the control panel ac master switch,goes to the cycling switch,from there,a light green and a dark green wire feed off to the compressor.I think this will help me get this ac system going.Its really getting hot here in Arizona.
By the way,I am origionally from Del Rio,Texas.Raised in San Antonio but found a good job here in AZ and have been here for quite a few years.
Mando

 

[Longroof79]

Welcome to the site, Mando.
It's been hotter than Hades out in your neck of woods. It sounds like you have a handle on how the a/c should function...and I'm sure it will be very welcome once it's operational.
I love my new a/c. It's been non-functional for way too many years. I really appreciate having it and riding in comfort.

 

[Texas82GP]

Glad I could help. After reading your post it jogged my memory. Those light green and dark green wires are definitely what you want to connect to the clutch cycling or low pressure switch you put on the accumulator. The pigtail connector is still readily available. Are you going R12 or R134A?

 

[mando13]

Thanks for the welcome Longroof79.Yes,its pretty hot out here in the desert.I need to get this AC going so that I can go cruising in this baby. Texas82,I have already put in the PAC 150 oil in the compressor and after I evacuate the system,I will re-charge it with R134.
Talk to you guys later and have a good day.
Mando

 

[mando13]

Well,we went ahead and evacuated and charged the AC system in my el camino yesterday but there is a problem somewhere.After charging it with R134A,I found out the there is very little air coming tru the vents,even at high speed.I can hear the blower motor and its running pretty fast so I don't think its the motor.I changed everything except the evacuator,could this be the problem?
Or, could it be a vacuum problem?A friend said to remove the dash to see whats going on under there with the vents but I don't want to do that unless I have to.Can anyone here give me some tips as to what may be the cause of not enough air coming tru.Also,the air is not as cold as it should be.I would appreciate any help from you guys.I am hoping to correct this problem before I melt here in AZ.
Thanks for your help.
Mando

 

[pontiacgp]

when you change the settings do you hear any doors opening or closing? Also do you have the pink plastic tube hooked to the manifold or vacuum reservoir?

 

[mando13]

Thanks for your reply.I will get back to it in the morning and than start the engine and move the head controls to see If I hear any doors opening.There is a ( I call it a canister on the firewall next to the blower case ) that has a vacuum tube connected to it.That tube does have vacuum.Maybe the canister that I mention here is the vacuum reservoir that you mention.
I will keep you posted tomorrow as to what I came up with.
Mando

 

[mando13]

I went ahead and cleaned out all the vents in the duct work and removed the control head to clean all electrical contacts and also all the vacuum lines to the control head.I than turned the engine on and the AC on and I get air tru the top and bottom vents but none tru the middle vents.I had removed the middle vents to see more clearly what was going on.I than accelerated the engine and as I did than,the main door right behind the middle vents opened up and all kinds of air came out tru the middle vents.I turned the AC off and that door closed down.I turned the AC on but this door will not open again.So,now I know that the problem is in this main door behind the center vents that is not opening up.My question,what drives this door? is it vacuum or some small motor?I tried to see if there was a vacuum line going to that door but I did not see anything.This door is in the middle of the duct work and I can't get to it from anywhere.
Have any of you had a problem with this door and can help me with some ideas or suggestions.When I bought this el camino,the control head/switching panel was missing so I bought this one from Ebay.Maybe its a bad panel.Are there any ways to check and see if this control head is working ok? Thanks to all for your help and suggestions.
Mando