A/C Switch, Lighting Switch, Fan Switch, Power Steering Switch (Code 31)
Disconnect 20-pin connector and measure voltage between terminal 7 and body ground. See Figure . With A/C switch in "ON" position, there should be 12 volts. With switch in "OFF" position, there should be no voltage. If not, inspect harness and repair if necessary. If harness is okay, check switches and replace if necessary. If okay, replace control unit.