Functional Test
WARNING: This page does not describe the selected car, but rather 26 other vehicles, including the 1996 Pontiac Trans Sport, 1996 GMC Yukon, 1996 GMC Vandura Special, 1996 GMC Vandura, and 1996 GMC Suburban. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Perform this check if sent here from chart.
- Idle engine for about 20 minutes until warm or until thermostat opens. Ensure coolant temperature is about 194°F (90°C). Select vent mode. Move temperature lever to coldest temperature setting. Select high blower speed. Air should exit instrument panel outlets and should be about the same temperature as outside air. Air should not exit floor outlets, defroster nozzles, or side window defogger outlets.
- Select heater mode. Move temperature lever to hottest temperature setting. Most air should exit floor outlets, with remaining air exiting defroster and window defogger outlets and should be hot. Air should not exit instrument panel outlets.
- Select defrost mode. Most air should exit defroster and defogger outlets, with a low volume of air exiting floor outlets. Move temperature lever to coldest setting. Air temperature should decrease to about the same temperature as outside air.
- Slowly turn blower motor speed control knob toward OFF position, stopping briefly at each intermediate position to check force of airflow exiting instrument panel center outlets to hear blower noise. Airflow and blower noise should decrease noticeably at each intermediate position.