Thermal switch — checking (Nissan Murano Z50)

The purpose of the thermal switch is to turn on the radiator's electric fan when the coolant reaches a certain temperature. The switch must be checked if the fan does not turn on when the radiator is hot, but the relay, fan motor, and thermostat are in order. If these parts are faulty, the thermal switch will not be able to turn on the fan because it will not be heated by the coolant.

Caution: The radiator fan may turn on automatically when the engine is off and the ignition is on. This is caused by residual heat from the engine. Therefore, when working in the engine compartment, turn off the ignition.

• Disconnect the plug connection of the thermal switch.
• Unscrew the thermal switch.

Caution: This will cause coolant to flow out of the hole in the thermostat cover. Place a container underneath to collect the liquid.

• Hang the thermal switch in a container of water, slowly heat the water, and measure the current flow with an ohmmeter. When switched off, no current should flow. When switched on, current must flow (the resistance is 0 ohms). The switch should click when turned off.

• After the container with water has cooled, check that the switch has switched.
• Screw in the thermal switch with a new sealing ring.
• Fill with coolant.
• Warm up the engine and let it idle until the fan comes on. Check the coolant level again.