Heater Output Temperature Check

Temperature Check:

HEATER OUTPUT TEMPERATURE CHECK
The heat output of the heater system can be checked with the following procedure.


Preparation
With the engine sufficiently cool, remove the radiator cap, start the engine, and allow it to idle. Set the heater controls to "HTR" mode, full "Red" (Hot) temperature, and "HI" blower speed. When coolant flow in the radiator is visible through the filler neck, install the radiator cap.


Temperature Check
When the engine is warmed up (after approximately 20 minutes of operation), the vehicle should be driven. An accurate thermometer should be used to determine the temperature of the outside air and the temperature of the air discharged at the floor outlets with the vehicle being driven at 48 km/h (30 mph). Minimum acceptable heater output temperatures at four different outside air temperatures are shown in the accompanying table.

Minimum acceptable heater output temperatures for outside air temperatures other than those shown can be approximated by using the Fahrenheit scale and rounding off the outside air temperature to the nearest 5 degrees. For every additional 5 degrees of outside temperature, an additional 1.8 degrees of heater output temperature should be allowed when the outside temperature is below 50 degrees. An additional 1.6 degrees of heater output temperature should be allowed for every 5 degrees of outside temperature when the outside temperature is above 50 degrees.