AC question

Long story short I finally got what I needed to get my AC back together in my 1986 LTL 9000. I believe when I first purchased it it was working correctly. Someone had added a power switch to power the compressor. There is a low and high side binary switch (2 prong) so I charged it up the other day, compressor kicks on, fan comes on right away. It did not cycle like it should. I walked away from my manifold to go see what the vents were doing in can and if it was cooling. There was condensation forming on lines and I thought I had it figured out. About 30 seconds later the high side line blew at the crimp, and out went all my Freon. My question is on a mechanical engine, how can I get the fan cycling correctly. If I am wrong please correct me, high pressure binary switch cuts off compressor if it’s gets to high, and kicks engine fan on as well? I’d like to try and trace these wires and get it cycling correctly and hopefully get this working correctly. Just stumped on where to start I guess. My other old truck that was set up like this I had to remember to kick the fan on when stopped or in slow traffic, because it wouldn’t cycle correctly. This used to cycle correctly, I haven’t had it going in about 3 years though. Any help or input is appreciated. Thank you also to note both low and high switches are new.

 

Thank you for the reply, I have 1 switch on low side line, and 1 on the high side line. Amy I missing a binary switch somewhere? I will try and get some decent pictures in the day light. Unfortunately as old trucks go someone was in this before me so I have no clue really what was done, just what I can see on the surface for now.

 

Update. Thought I had it figured out. Replaced the high side line. Did a long vacuum on it last night, held a vacuum overnight, charged it. It was cycling like it should, evaporator was getting cold and dripping water. Best I saw cab/ sleeper vents was 75*. It is 100 out today. Low side hovering around 30, high side 300-375ish. Low side seems low, high seems high. This was with roughly 3.75 lbs of Freon. So I let it idle and cycle a bit. It would go up to around 375 on high side, fan would kick on, drop to 300 high side and kick off. The high pressure switch has power to it with key on. The fan its self takes air pressure to turn off. What has me stumped now tho is the compressor itself started kicking off. Then it would shoot to about 90 low side, 200ish high side and compressor would kick on. Did this for a bit and now can’t get compressor to cycle on at all. I am stumped, and it can be anything at this point. I’m not sure what they did when they wired this up this way. I feel I had it almost, and maybe I’m missing something stupid, or overcharged it. Can’t find any info for a LTL with a sleeper.