Heater Lockout Switch: Testing and Inspection

1. DRAIN ENGINE COOLANT FROM RADIATOR.

HINT: It is not necessary to drain out all the coolant.




2. REMOVE WATER TEMPERATURE SWITCH.
a. Disconnect the connector.
b. Remove the water temperature switch.




3. INSPECT SWITCH CONTINUITY.
a. Using an ohmmeter, check that no continuity exists between the terminal and switch body when the coolant temperature is above 83 °C (181 °F).
If continuity exists, replace the switch.
b. Using an ohmmeter, check that continuity exists between the terminals when the coolant temperature is below 90 °C (194 °F).
If no continuity exists, replace the switch.

4. INSTALL WATER TEMPERATURE SWITCH.
a. Install the water temperature switch.
Torque: 34 Nm (350 kg.cm, 25 ft.lb)
b. Connect the connector.

5. FILL WITH ENGINE COOLANT.