A/C Control Unit
- Disconnect A/C Control Unit (ACCU) 10-pin connector and inspect connector and wiring for damage. Turn ignition on, A/C switch to ON position, temperature control to maximum cooling and blower switch to high. Using a DVOM set to appropriate test function, inspect harness side of connector. See Fig 1
. Go to next step. If all test readings are as specified, replace A/C control unit.
- Terminal No. 1 (Green/White wire) is A/C compressor relay. When ACCU has received signals from pressure and temperature sensors confirming A/C operation is okay, A/C switch is on, and blower motor switch is on, battery voltage should be present.
- Terminal No. 3 (Green wire) is ACCU power supply when A/C switch is in A/C mode. With ignition and blower switches on, and A/C switch to second level, battery voltage should be present.
- Terminal No. 5 (Blue/Green wire) is ACCU power supply when A/C switch is in economy mode. With ignition and blower switches on, and A/C switch to first level, battery voltage should be present.
- Terminals No. 2 and 7 (Black wire) are A/C control unit grounds. There should be zero volts at all times.
- Terminal No. 8 (Blue/Yellow wire) is air thermo sensor power supply. With ignition, blower and A/C switches on, approximately 5 volts should be present.
- Terminal No. 10 (Blue/White wire) is air thermo sensor signal. When sensor temperature is 77°F (25°C) and measured resistance is 1500 ohms, there should be approximately 2.2 volts present.
- Terminal No. 4 (White/Blue wire) is air inlet sensor power supply. With ignition, blower and A/C switches on, approximately 4.8 volts should be present.
- Terminal No. 9 (Yellow/Green wire) is air inlet sensor signal. When sensor temperature is 77°F (25°C) and measured resistance is 1500 ohms, there should be approximately 3.3 volts present.
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA