Functional Test - Heater - Without A/C

Before beginning the functional test of the heater system, the vehicle should be idling with the coolant hot and the thermostat open. Coolant temperature should be 90°C (194°F). Even if a problem is found during any intermediate step of the functional test, the test should be completed before repair is started.

NOTICE: Some air bleed will occur through defroster vent in all modes. Side window defogger outlets should have air flow in all mode selections. Lap vents must be checked for the following reasons:

1. Barrel rotation.
2. Vane operation.
3. Barrel and vanes must hold position in high blower.

Remarks:

A. Engagement of detent must be felt in each mode.
B. Noticeable blower speed increase must occur from low to Med 1, Med 2 and high.
C. Listen for changes of air noise due to recirculation door closing.