Blower Motor Always On - Front

Blower Motor Always On (Front):

CIRCUIT DESCRIPTION
The airflow is controlled by modulating the commanded blower voltage. The blower voltage varies the blower speed. The blower is a function of the program number when the blower is under automatic control. Adjustments are made based upon the following factors:
^ The vehicle speed
^ The coolant temperature
^ The sun load sensor

The following special cases may override the normal operation of the blower:
^ Limit snow ingestion
^ Purge the air ducts
^ Cool the instrument panel cluster
^ Enhance the heater warm-up performance

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
1. Performs the Diagnostic System Check before continuing with the diagnosis.
2. The Scan Tool checks input voltage at the blower motor.
3. The Scan Tool checks for a short on the power and ground sides of the blower motor.
4. Checks the status of CKT 754 (blower speed control input to the blower motor). Also verifies the Heater and A/C Programmer output.