Slow Warming
- Incorrect operation of controls.
- Low coolant level.
- Control cables not attached.
- Blower motor not operating.
- Air doors not fully opening.
Exhaust Fumes In Vehicle
- Leaking seal between engine compartment and plenum.
- Leaking seal between air inlet duct and dash.
Cold Drafts On Floor
- Improper operation of vent cables.
Insufficient Heat to Rear Seat Area
Drop In Heater Air Temperature At Any Blower Motor Speed
- Low engine coolant level.
- Air in cooling system.
Failure Of Cooling System To Warm Up
- Incorrect or inoperative engine thermostat.
- Incorrect coolant level.
No Coolant Flow Through Heater Core
- Kinked heater hoses.
- Plugged heater core.
- Inoperative water valve (auxiliary heater only).
Inadequate Removal Of Fog Or Ice
- Air door not opening.
- Defroster door not opening.
- Temperature door not opening.
- Obstructions in defroster outlets at windshield.
- Dinged defroster outlets.
- Blower motor feed or ground disconnected.
- Blower motor or blower motor fuse inoperative.
- Inoperative blower motor switch.
Too Warm In Vehicle
- Temperature door improperly adjusted.
- Incorrect operation of controls.
Blower Motor Not Operating
- Blown fuse.
- Inoperative motor.
- Open circuit.
- Inoperative blower motor switch.
- Shorted or open blower resistor.