Front

Steps 1-12:

Steps 13-18:

CIRCUIT DESCRIPTION
The airflow is controlled by modulating the commanded blower voltage that varies the blower speed. Under automatic control, the blower adjustments are made based upon the following factors:
^ The vehicle speed
^ The coolant temperature
^ The sun load sensor

Special cases exist that may override the normal operation of the blower in order to limit the following conditions:
^ Snow ingestion
^ Purging the air ducts
^ Cooling the instrument panel cluster
^ Enhancing the heater warm-up performance.

DIAGNOSTIC AIDS
If the blower is inoperative in the normal operating procedure, but operates properly in the override, the IPC or the data line between the IPC and the heater and A/C programmer are suspect.