Preliminary Diagnosis

Start all diagnosis with the air conditioning functional test. Finish all diagnosis by repeating air conditioning functional text to ensure correct diagnosis.

Some diagnostic procedures require the ignition switch to remain in the ON position for extended time periods while tests are performed. Low battery voltage may result, causing erroneous voltage readings.

When vehicle system voltage becomes low, it is advisable to connect a battery charger to the vehicle's electrical system and apply a slow charge while testing.