A/C wiring questions! Something looks funky to me.

Hey Everyone,

New to the forum here! Just got an 88 Mighty Max and everything runs really well. The only issue Is the A/C does not blow cold. I checked all the fuses (under the driver side dash) and tried to follow what little I could find of wiring diagrams. I ordered a Haynes manual that will be here on Thursday. I started ohming out from my a/c and something seemed off with the signal. I cut off some old electrical tape and found that the positive from my A/C is teed into another wire that goes to this small box with two vacuum lines attached. I couldn't find a part number on the part nor find anything that resembled it in the few wiring diagrams I could find. Should Any of the wires off the a/c compressor be teed into anything? also what is the weird tiny box thing with two vacuum lines? I uploaded pictures of the box and the "splice". The green circle goes to my a/c and the red circle goes to the box. Also the box looks like it's missing something??

Thanks for any/all help :)

At a guess it uses vacuum to idle up the engine when the A/C is on. If that vacuum circuit is not functioning my bet is it won't idle up and/or kick the compressor on. Does the compressor clutch work when you turn the A/C on? If it kicks on then it has to be a gas charge problem. Where does that 2 pin plug connect to? And when is the tee'd connection live?

So when I jump the compressor I can hear it click, but not when normally turning on the a/c. It will also idle rough when the a/c is turned on, so you might be onto something. When I get out of work I'll be able to figure out where the connector goes and when it's live.

Problems is you don't know what has been done to it by PO's. Wiring is the worst to deal with after someone decides to ghetto fix a fault. They may have bypassed something to get it to 'work' rather than fix the initial issue.

So I was able to follow it under the dash were it gets lost in the sea of wires and it's super uncomfortable to be under there for an extended time. I just ended up unplugging it and it didn't seem to effect anything. I drove it into town for about 30-40min and it drove the same. I will say that even with the compressor jumped the a/c still blows hot so, I'm guessing even if I managed to fix the wiring the compressor is probably faulty?

Only thing you can do is try to regas it and see if it's leaking anywhere. It may not be a bad compressor, just a failed seal somewhere. You will probably be up for a new dryer but at least you can get those off ebay at pretty reasonable prices...