I have a 1998 chevy K1500 4WD and the AC doesnt switch on when i hit the AC button on the dashboard. I can run a jumper directly from the battery to the clutch on the compressor and it will engage. But when i reconnect the plug (from the wiring harness) to the clutch on the AC Compressor nothing happens. Ive installed a new module on the dashboard, a new AC cycling switch and checked the fuses and replaced the relay already. I had other environmental controls problems with the inside cab blend doors so i replaced both of those. All that works now but still nothing on the AC. No the system is not charged with refrigerant.