AC–64 AIR CONDITIONING SYSTEM – TROUBLESHOOTING 4 Check voltage between terminal MGC of A/C amplifier connector and body ground. ON Connect MGC BE3840 N08802 P 1. Remove A/C amplifier with connectors still connected. 2. Start the engine. C Check voltage between terminal A/C IN of A/C amplifier connector and body ground when magnetic clutch is on and off by A/C switch. OK Magnetic Clutch Voltage ON Below 1 V OFF 4 – 6 V NG OK Go to step 7 . 5 Check voltage between terminal A/C of ECM and body ground. ON ECM Connect BE3840 AC2997 N08821 A/C P 1. Remove the ECM with connectors still connected. 2. Turn ignition switch on. C 1. Push the A/C switch on. 2. Measure voltage between terminal A/C of the ECM connector and body ground. OK Magnetic Clutch Voltage ON Below 1 V OFF 10 – 14 V OK NG Check and replace ECM. 6 Check for open and short in harness and connector between A/C amplifier and ECM (See page IN–30). OK NG Repair or replace harness or connector. Check and replace A/C amplifier.