Temperature Control

The temperature valve is controlled by the electric actuator. The motor within the electric actuator positions the valve based on the temperature knob location.

When the temperature knob is in the Blue (Cold) position, the air that is delivered by the HVAC system is unheated. When the temperature control is in the Red (Hot) position, all of the air that passes though the heater/vent module is heated before the air is discharged. Intermediate positions of the temperature control result in a mixture of heated and unheated air in order to provide more moderate air temperatures.

As the temperature control is moved away from the Blue (Cold) position, the temperature valve moves away from the heater core. This allows some air to flow through the heater core. As the temperature control is moved farther toward the Red (Hot) position, the following actions occur:
1. The temperature valve is turned farther away from the entrance to the heater core
2. The airflow increases through the heater core

Heating a greater portion of the total airflow in this manner results in a warmer discharge of air from the outlets.

When the temperature control is in the full Red (Hot) position, the temperature valve blocks off the passage that allows air to bypass the heater core. This causes all of the airflow to go through the heater core for maximum heating. This method of temperature control provides a rapid response to any change in temperature selection throughout the entire range when the engine is warmed up.