1987 R10 Silverado 305TBI to 5.3 LS swap Air condition control question

[mcgarijs]

Current Air condition compressor is controlled by the ECM which is connected to the AC controls on the dash. Doing a 5,3 gen 3 LS swap now and cant find a drawing or anyone to help with how to interface turning on and off the compressor with new LS setup that doesnt talk to the old AC controls.

[Captkaos]

87 ECU doesn't control the AC.  There is only Blower and Clutch all controlled via the AC switch panel.
http://www.73-87chevytrucks.com/techinfo/7387CKMans//Service/ST_330_87_1987_Chevrolet_Light_Duty_Truck_Service_Manual.pdf#page=93
Electrical
http://www.73-87chevytrucks.com/techinfo/7387CKMans//Wiring/ST_350_87_1987_Chevrolet_GMC_Light_Truck_Wiring_Manual_Complete_11x17.pdf#page=27

What AC pump are you running?