Hi, I have a 95 4WD Blazer. The AC has not worked in the two year I have owned the truck. The previous owner said it just needed to be charged. I recharged the refrigerant and no luck. There is a switch on the dash was installed by the previous owner that I was told was for the AC Compressor. The switch lights up but the compressor doe snot come on. I found a connector on top of my alternator with a green and black wire. The black wire feeds into a butt and end connector and comes out red with a fork terminal that is unattached. There is also a green wire that goes into another butt and end connector and comes out yellow with a 10 amp fuse another connector now it is red and runs under the engine and screwed down to a bolt into on the other side of the car. There is also a thick bundle of wires below and toward thedash , there was a green wire sticking out and it was live. It looks like it was stripped and pulled out slightly. The red forkterminal wire might have been attached to the green bundle wire for power? Sorry if I am all over the place but it's amess. Thanks in advance I also have pics I can send if that helps.

 

Wow. Someone hacked the living hell out of that one, and would've been better off to just fix it the right way. Without looking at the wiring, it's hard to say.
As for the wiring, better to post some photos here. I've got a feeling the previous owner didn't tell you everything. I sure as hell wouldn't have taken his word for it that all it needs is a recharge, I can tell you that much.
If you're anywhere near Colorado Springs, I'd be happy to take a look at it for you sometime during the weekend, but I have a sinking feeling there's a lot which needs to be undone with this vehicle.

 

I am attaching photos. Thanks for the offer of looking at it but I'm in Massachusetts.
Pic 2: The red wire below the yellow one with the fuse has the fork terminal that is unattached.
Pic 3: This is where I found the stripped green wire coming out of this bundle.

 

It looks to me like he set up something to jump the low pressure switch - IMO, useless as **** on a bull, especially when it wouldn't have been much more painful to just replace the low pressure switch. The problem with such a setup is that AC systems are set to operate within certain pressure ranges. The high and low pressure switches ensure the system pressure stays within these ranges, cutting off and actuating the compressor clutch as needed. The compressor isn't supposed to stay on the whole time - it cycles on and off. Too little pressure, and the end result is insufficient cooling. Too much pressure, and the end result is insufficient cooling, and eventual system damage. Even if you did have a permanently attached manifold gauge in the cabin somewhere, you would have to cycle the clutch off and on manually, and that would create quite a distraction.