Coolant Temperature Sensor / Switch HVAC: Testing and Inspection

1. Immerse the water temp. sensor in water.
2. Using a stove heating the water measure the resistance between terminal 1 and terminal 2.




3. Check the resistance value is within specification as shown in the graph.

Water temperature Resistance
25° C 12.5 ± 0.5 K Ohms
60° C 2.5 ± 0.3 K Ohms