Air Conditioning Switch

NOTE: A number of problems, in addition of a defective A/C switch, can cause A/C system malfunctions.

- With engine at operating temperature and running at idle, probe ECM terminal 15 (green wire, ECM 18 pin connector) with positive voltmeter lead and ground negative lead.
- Turn A/C switch "ON." Meter should read battery voltage, indicating that switch is functioning properly and A/C request signal is reaching the ECM.
- If problems are indicated, check wiring circuits and connections. For complete diagnosis and repair information on the air conditioning system, refer to HEATING, VENTILATION AND AIR CONDITIONING.