A/C Compressor

What wires feed power to the ac pump? What color? I wanna make sure it turns on before i go buying refrigerant

 

It is a single wire that comes out with the vacuum hoses thru the firewall.

As long as that car has been sitting, you will need more than just freon.

 

What all do i need?

 

You need to have it tested to make sure it will retain "leaks" refrigerant, hoses and o-rings will most likely need replacing, compressor may not be operational. Heat/AC box needs to be checked for cracks that will leak water in cabin if cracked or drain hose is not attacked to to drain nipple. Long story, short, liked Craig mention you will need more than refrig. if you want it to work w/o a lot of money & time spent as it suppose too.

 

The compressor doesnt come on when i turn the ac on. I have it plugged in and the fuse is good

 

To put it bluntly, your chances of winning Powerball are greater than a '70 A/C system not having leaks.

 

I don't know if a 70 has a binary switch but if it does that is why it won't come on.

 

I just want to make the compressor work. I figured that would be a good starting point. The blower works also. Well, like a nearly 50 year old motor would be expected to work. As a side note, my windshield wipers even work. That impressed the heck outta me.

 

Have you identified the power lead going to the AC clutch? If so does it show voltage when you select AC? If it does and the compressor does not engage, you will probably need a coil and/or clutch. Even if it engages, the compressor may or may not be any good.

 

Well, as far as it possibly not being any good, thats what i'm aiming to find out. I haven't tested the wire going to it. Ill try that tomorrow and see if it helps. Is the power for the a/c clutch on with the key on? If so, wouldn't I be able to hear it engage when i flip the switch over to a/c?

 

It kind of reminds me of the pto clutch in my old craftsman 2. It also uses an electromagnet.

 

just stick 12V to the clutch wire, that should let you know if the clutch works...
if you go through the switch the binary switch will need to be satisfied for it to work.

 

how exactly can i get to the binary switch to inspect it?

 

Switch is on plenum but if there isn't vacuum connected to the switch actuator, it'll never turn on the compressor. After you connect vac you'll probably need to find a dozen leaks.

 

Here is the switch that controls the compressor. The 70-72 switch (left) is replaceable...the 73-77 (right) is made onto the vacuum switch.