Having hell making a/c work

98 OBS truck, was a 4.3 V6. Now it's a 5.3 and I made my own a/c relocation using an R4 compressor. I plugged in all of the factory wiring and could never get it to enable the compressor. Checking the original pcm connections, I decided they weren't all there and decided to wire it up myself. Here's where I am now, all wired standalone.

Wire from the interior button to positive side of relay
Wire from stock switch on the accumulator providing ground to relay
Relay provides positive power to the compressor
That way, without either one the system is off.

Apparently that switch doesn't make it cycle, because it just stays on all the time. The switch is constantly providing a ground so it just stays on. If I unplug that switch, it does turn off. stays running at 22psi and never changes. Also doesn't get cold, lol.

What am I doing wrong?

Maybe this will help. On your '98, the A/C's dash switch control provides a ground, not a 12 volt positive. I would recommend buying the GM Service Manuals(two books) for your 1998 C/K 1500 truck. All the wiring diagrams & everything else is in them. You will need to reference them often.

The wire right from the dash switch out to the high pressure switch that turns everything on is most definitely 12v. My meter said so when I checked it, and as connected above to the positive side of the relay coil with a negative on the opposite side it does turn on the relay.

If in fact I'm missing something and you are correct, the relay shouldn't be turning on and enabling the compressor, right?

Regardless, the other side of the relay coil is grounded through the stock "cycling switch" that is on the accumulator, and it isn't turning the compressor on and off. Regardless of whether I'm putting 12v or ground through it, that switch isn't disconnecting and turning off the compressor based on pressure and that's what I don't know how to fix.

I've been told that I may just need to use a low pressure switch form something like a 88 truck that only uses that one switch for cycling, and that one should then turn the compressor on and off? It was said that maybe the stock 98 doesn't simply connect and disconnect, but it is actually just varied signal since it originally went to the pcm, and that's why it won't disconnect it's side of the coil to cycle the compressor. I have no verification for any of that though