Electric Fan E46 Circuit Diagram

The electric fan in a BMW E46 is a critical component of the cooling system. It helps to maintain the engine at a safe operating temperature by circulating air through the radiator. If the fan fails, the engine can overheat and potentially damage itself. The electric fan is controlled by a temperature sensor located in the thermostat housing. When the coolant temperature reaches a certain point, the sensor sends a signal to the fan control module (FCM). The FCM then turns on the fan motor, which starts to circulate air through the radiator. The fan motor is a brushless DC motor that is controlled by the FCM. The FCM sends a variable voltage signal to the motor, which causes it to spin at different speeds. The faster the motor spins, the more air is circulated through the radiator. The electric fan is an important part of the BMW E46 cooling system. If the fan fails, it can cause the engine to overheat and potentially damage itself. If you suspect that the fan is not working properly, it is important to have it checked by a qualified mechanic. ### Electric Fan E46 Circuit Diagram The following diagram shows the electric fan circuit for a BMW E46:

The diagram shows the following components: *

Thermal switch:

This switch is located in the thermostat housing and sends a signal to the FCM when the coolant temperature reaches a certain point. *

Fan control module (FCM):

This module receives the signal from the thermal switch and turns on the fan motor. *

Fan motor:

This motor is a brushless DC motor that circulates air through the radiator. *

Fan resistor:

This resistor is used to control the speed of the fan motor. The fan motor is connected to the FCM by a three-wire connector. The red wire is the power wire, the black wire is the ground wire, and the green wire is the control wire. The fan resistor is connected to the FCM by a two-wire connector. The red wire is the power wire, and the black wire is the ground wire. The fan motor and resistor are mounted to the radiator shroud. The fan motor is located at the front of the shroud, and the resistor is located at the back of the shroud. ### How to Test the Electric Fan If you suspect that the electric fan is not working properly, you can test it using the following steps: 1. Turn off the engine and allow it to cool down. 2. Locate the fan motor and resistor. 3. Disconnect the three-wire connector from the fan motor. 4. Connect a multimeter to the fan motor terminals. 5. Turn on the ignition switch. 6. The fan motor should start to spin. 7. If the fan motor does not spin, replace it. 8. Reconnect the three-wire connector to the fan motor. 9. Connect a multimeter to the fan resistor terminals. 10. Turn on the ignition switch. 11. The fan resistor should show a resistance of approximately 2 ohms. 12. If the fan resistor does not show a resistance of approximately 2 ohms, replace it. ### Conclusion The electric fan is an important part of the BMW E46 cooling system. If the fan fails, it can cause the engine to overheat and potentially damage itself. If you suspect that the fan is not working properly, it is important to have it checked by a qualified mechanic.

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