A/C Control Assembly Inputs
Remove A/C control assembly. See A/C CONTROL ASSEMBLY under REMOVAL & INSTALLATION. Leave electrical connectors attached to A/C control assembly. Using DVOM to backprobe at appropriate terminals, check for voltage or continuity as specified. See A/C CONTROL ASSEMBLY INPUT SPECIFICATIONS table. See Fig 1. If readings are as specified, substitute known-good A/C control assembly and retest system. If readings are not as specified, repair affected circuit as necessary and retest system. See WIRING DIAGRAMS .
A/C CONTROL ASSEMBLY INPUT SPECIFICATIONS
| Test Between Terminals No. | Condition | Result |
|---|---|---|
| A8-Ground | Under All Conditions | Continuity |
| A9-A10 | Mode Selector In DEF Or F/DEF Position | Zero Volts |
| Mode Selector In Any Position Except DEF Or F/DEF | B+ Voltage | |
| A11-Ground | Blower Switch On | B+ Voltage |
| A11-B6 | Refrigerant Pressure 28-455 PSI | B+ Voltage |
| Refrigerant Pressure Not 28-455 PSI | Zero Volts | |
| A12-Ground | Blower Switch On | B+ Voltage |
| Blower Switch Off | Zero Volts | |
| A14-Ground | Ignition Switch In ACC Position | B+ Voltage |
| B8-Ground | Compressor Clutch Engaged | B+ Voltage |
| Compressor Clutch Disengaged | Zero Volts | |
| B13-Ground | Air Inlet Switch In FRESH Position | Less Than One Volt |
| Air Inlet Switch In RECIRC Position | B+ Voltage | |
| B15-Ground | Air Inlet Switch In RECIRC Position | Less Than One Volt |
| Air Inlet Switch In FRESH Position | B+ Voltage | |
| B18-Ground | A/C Switch On | Zero Volts |
| B19-Ground | A/C Switch On | Less Than One Volt |
| A/C Switch Off | B+ Voltage | |