ok i have ~30psi in the system. i checked the wiring diagram and found the AC relay signal wire is 1L at the stock ECU (which is on the body half of the stock ECU harness) and the diagram says it is 12v output to the A/C relay, so i give it 12v and it doesn't kick on. i've also checked the AC fuse and it's good.
i need some help here.
i guess the next thing is the pressure sensor?

 

i grounded the signal wire and it works fine now. i'm just using a manual switch to turn the compressor on/off

 

they have it going thru the ecu so the ecu knows you turned on the a/c, if you just ground it, it should work like normal