Functional Test - Without A/C

Control Assembly Operational Test:

NOTICE: 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 close to 90 °C (194 °F). During the functional test, the operating efforts of the mode lever and the temperature lever should be evaluated. Even if a problem is found during any intermediate step of the functional test, the test should be completed before repair is started refer to image for Control Assembly Operational Test.

TEST DESCRIPTION
1. Cycle the temperature lever to the extreme ends of travel in the slot of the control assembly dial to assure that the cable is properly adjusted.
2. Set the mode lever to "VENT."
^ Air at nearly the same temperature as the outside air should come from the instrument panel outlets.
^ Air should not come from the floor outlets, the defroster nozzles or the side window defogger outlets.
3. Move the mode lever to the "HTR" position.
^ Most of the air should come from the floor outlets with the remainder coming out of the defroster nozzles and defogger outlets.
^ Air should not come from the instrument panel outlets in the "HTR" position.
4. Move the mode lever from the "HTR" position to the "DEFROST" position.
^ Most of the air should be discharged onto the windshield from the defroster nozzles.
^ A small amount of air should also be discharged from the floor outlets.
5. Move the temperature lever back to the full "COOL" position and check to be sure the air temperature drops back to nearly the temperature of the outside air once again.
6. Slowly turn the blower switch toward "LO," stopping briefly at each intermediate blower speed position to notice the force of the airflow coming from the instrument panel center outlets and the sound of the blower.
^ Both the airflow and the blower noise should reduce noticeably at each intermediate step.

NOTE: For further system tests, Refer to Insufficient Heating. Testing and Inspection