B1413
AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1413/13: Evaporator Temperature Sensor Circuit
B1413/13 - Evaporator Temperature Sensor Circuit
DESCRIPTION
The No. 1 cooler thermistor (evaporator temperature sensor) is installed on the evaporator in the air conditioner unit to detect the cooled air temperature that has passed through the evaporator and control the air conditioning. It sends appropriate signals to the air conditioning amplifier. The resistance of the No. 1 cooler thermistor (evaporator temperature sensor) changes in accordance with the cooled air temperature that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The air conditioning amplifier applies voltage (5 V) to the No. 1 cooler thermistor (evaporator temperature sensor) and reads voltage changes as the resistance of the No. 1 cooler thermistor (evaporator temperature sensor) changes. This sensor is used for frost prevention.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. READ VALUE USING TECHSTREAM (EVAPORATOR FIN THERMISTOR)
(a) Use the Data List to check if the evaporator fin thermistor is functioning properly.
Air Conditioner
OK:
The display is as specified in the normal condition.
NG -- INSPECT NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR)
OK -- REPLACE AIR CONDITIONING AMPLIFIER Removal
2. INSPECT NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR)
(a) Remove the No. 1 cooler thermistor (evaporator temperature sensor) connector Removal.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NOTICE:
* Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
* When measuring, the sensor temperature must be the same as the ambient temperature.
HINT
As the temperature increases, the resistance decreases (see the graph).
NG -- REPLACE NO. 1 COOLER THERMISTOR Removal
OK -- REPLACE AIR CONDITIONING HARNESS Disassembly