Electric Cooling Fan
| ITEM | DESCRIPTION |
|---|---|
| 1 | Mounting lug |
| 2 | Electric cooling fan - auxiliary |
| 3 | Cooling fan shroud |
| 4 | Speed flaps |
| 5 | Mounting lug |
| 6 | Electrical connectors |
| 7 | Mounting lug |
| 8 | Electric cooling fan - main |
| 9 | Mounting lugs |
| 10 | Speed flaps |
Vehicles have two variable speed electric cooling fans to help regulate the engine coolant temperature. The fan shroud is attached to the rear of the radiator. The shroud incorporates speed flaps, which pivot open to allow engine compartment cooling at speed.
Each electric cooling fan is operated by a control module, integrated into their electric motor, which is controlled by the PCM. Electrical connectors at the right side of the fan shroud provide the interface between the cooling fan harnesses and the vehicle wiring.
The control module of each electric cooling fan is provided with:
- A battery power supply from the Auxiliary Junction Box (AJB).
- An ignition signal from the PCM relay in the Engine Junction Box (EJB).
- A Pulse Width Modulation (PWM) signal from the PCM.
- A ground.
To control each electric cooling fan, the PCM varies the duty cycle of the PWM signal. The cooling fan control module translates the duty cycle into a fan target speed and sets the output current to the fan motor accordingly.