Hello. I have an 81 silverado with only 46k miles and want to restore back up. The a/c system has a throttle solenoid, sometimes called an idle compensator, on the carb linkage that when the a/c compressor clutch engages this thing pushes the throttle up so the engine doesn't stall. It doesn't work anymore and it is an electrical problem. This solenoid itself is vacuum controlled, but an electric valve shifts and causes the vacuum to then go to the solenoid when compressor kicks in. This side of things is good. The electric coil itself is also good. The problem is there is a relay that sends a ground to the coil therefore making everything work properly. The relay itself is good and seems to be maybe a break in a wire leading up to the relay. I just need a good schematic for the truck and I then can figure it out from there. Also a good schematic for the cruise control system too, vacuum and electrical side. Truck is 81 3/4 ton 2 wheel drive with 454 engine. Vin is 1GCGC24W8BJ125938. Thanks