Initial Inspection and Diagnostic Overview

HEATER, AIR CONDITIONING AND VENTILATION DIAGNOSTIC TROUBLESHOOTING STRATEGY

CAUTION: If the condenser fan does not run as the air conditioning is on under low load, disconnect the negative battery cable for a moment and then reconnect it. Then a trouble symptom can be checked for five minutes after the condenser starts running.

Use these steps to plan your diagnostic strategy. If you follow them carefully, you will be sure that you have exhausted most of the possible ways to find a heater, air conditioning and ventilation fault.
1. Gather information from the customer.
2. Verify that the condition described by the customer exists.
3. Find the malfunction by following the Symptom Chart.
4. Verify malfunction is eliminated.