Heating Insufficient

Heating Insufficient

The following problems may cause insufficient heating outside the heater system:

* Low coolant level
* A faulty thermostat
* A partially or fully clogged heater core or hose
* An obstruction to air circulation
* An air leak past a faulty seal into the passenger compartment

For an organized diagnosis procedure, refer to Heater Blower Controls System Check (Insufficient Heat) HVACHeater Blower Controls System Check (Temperature Control Effort) Heater Blower Controls System Check (Temperature Control Effort)Heater Blower Controls System Check (Blower Noise) Heater Blower Controls System Check (Blower Noise).

On the 7.2L Caterpillar(R) engine-equipped vehicles, if you must idle the engine for a long period of time when the outside temperature is cold, the heater may blow out cold air. This is normal. When you increase the engine speed, the heater should blow out warmer air. If the heater does not produce warmer air, the coolant level may be low. For an organized diagnosis procedure, refer to Heater Blower Controls System Check (Insufficient Heat) HVACHeater Blower Controls System Check (Temperature Control Effort) Heater Blower Controls System Check (Temperature Control Effort)Heater Blower Controls System Check (Blower Noise) Heater Blower Controls System Check (Blower Noise).