Chart 2 Blower On All the Time

CIRCUIT DESCRIPTION

The airflow is controlled by modulating the commanded blower voltage which varies the blower speed. The blower is a function of the program number when it is under automatic control with adjustments being made based on vehicle speed, coolant temperature, and the sun load sensor. There are special cases which may override the normal operation of the blower to limit snow ingestion, purging air ducts, cooling the instrument panel cluster, or enhancing heater warm-up performance.

TEST DESCRIPTION

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