## Air Conditioning

#### A/C Pressure Switch Circuit Troubleshooting (cont'd)

21-79

6. Reconnect the A/C pressure switch 2P connector.

7. Disconnect the heater control panel connector A (14P).
8. Turn the ignition switch ON (II).
9. Measure the voltage between the No. 4 terminal of heater control panel connector A (14P) and body ground.

HEATER CONTROL PANEL CONNECTOR A (14P)

Is there battery voltage?

YES - Check for loose wires or poor connections at heater control panel connector A (14P) and at the A/C pressure switch 2P connector. If the connections are good, substitute a known-good heater control panel and recheck. If the symptom/indication goes away, replace the original heater control panel.

NO - Repair open in the wire between the heater control panel and the A/C pressure switch.

10. Make sure the A/C switch is OFF.

11. Measure the voltage between the No. 9 terminal of under-dash fuse/relay box connector F (12P) and body ground with the under-dash fuse/relay box connectors connected.

UNDER-DASH FUSE/RELAY BOX CONNECTOR F (12P)

Wire side of female terminals

Is there battery voltage?

YES - Repair open in the wire between the under-dash fuse/relay box and the A/C pressure switch.

NO - Refer to the multiplex control system (see page 22-268).

12. Check for proper A/C system pressure.

Is the pressure within specifications?

YES - Replace the A/C pressure switch.

NO - Repair the A/C pressure problem.