Q&A

 Master

First, Check your coolant level. The cooling system must be in good working condition, thermostat working properly etc. If the floor outlet air temperature is insufficient, check that the cooling system is operating to specifications. Both heater hoses should be HOT to the touch (the coolant return hose should be slightly cooler than the supply hose). If the coolant return hose is much cooler than the supply hose, locate and repair the engine coolant flow obstruction in heater system.
POSSIBLE LOCATIONS OR CAUSE OF OBSTRUCTED COOLANT FLOW
Pinched or kinked heater hoses. Improper heater hose routing.
Plugged heater hoses or supply and return ports at cooling system connections. Plugged heater core. Air locked heater core.
Restrictor in backwards. If coolant flow is verified and the heater floor outlet temperature is insufficient, a mechanical problem may exist.

POSSIBLE LOCATION OR CAUSE OF INSUFFICIENT HEAT
Obstructed cowl air intake. Obstructed heater system outlets.
Blend-air door not functioning properly.

TEMPERATURE CONTROL
If heater floor outlet temperature cannot be adjusted with the heater-A/C control temperature control, one of the following could require service:
Blend-air door binding.
Faulty blend-air door motor.
Improper engine coolant temperature.
Faulty heater-A/C control.