Test B: Insufficient, Erratic, or No Heat

PINPOINT TEST B: INSUFFICIENT, ERRATIC, OR NO HEAT

B1-B4:

B4 Continued:

Normal Operation
Under normal operation, when heat is selected on the temperature control switch and the blower motor switch is turned on, the blower motor directs air through the heater core. The heater core is filled with heated engine coolant.

Possible Causes
- engine cooling system
- temperature control switch
- temperature control cable