Wet Arm Heater (NAH)

Wet-Arm Heater (NAH)

For the first time in a BMW, a wet-arm heater is used for the E65/E66. On the E65/E66, there are no conventional heated washer jets in the hood.

In the wet-arm heater, the hoses for the washer fluid are in the wiper arm. This part of the washer fluid hose is electrically heated. The outlets of the windshield washer system are integrated in the wiper arm.

The washer fluid hose is heated using a PWM signal to control the current flow:

- With terminal R "on"
- Depending on the ambient temperature
- Depending on the battery voltage: with power reduction (battery load with priority 5, 6 via CAN) the power supply to the wet arms is decreased in half.

This can double defrosting times compared with normal times. The wet-arm heater is switched off while terminal 50 is "on".