Evaporator Temperature Sensor Test

Remove the evaporator core and the evaporator temperature sensor (see BLOWER/EVAPORATOR UNIT REMOVAL/INSTALLATION ).
Dip the sensor in ice water, and measure the resistance between its terminals.

Fig 1: Measuring Resistance Between Evaporator Temperature Sensor Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Then pour warm water on the sensor, and check for a change in resistance.
Compare the resistance readings with the specifications shown in the graph; the resistance should be within the specifications.

Fig 2: Resistance And Temperature Graph
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If the resistance is not as specified, replace the evaporator temperature sensor (see BLOWER/EVAPORATOR UNIT COMPONENT REPLACEMENT ).