Rear Window Defroster: FB

Rear Window Defroster: FB

Thawing phase
After terminal 15 new start and after being switched on for the first time, the time interval for the rear-window defroster is determined in order to achieve an optimum thawing effect.
- Thawing time at outside temperature > 15 degree C = 10 minutes
- Thawing time at outside temperature < 15 degree C = 17 minutes

Undervoltage cutout does not take place during the thawing phase

After-heating phase
In order to protect the battery charge level, after the thawing time has elapsed for the first time, the rear-window defroster is only activated for 5 minutes every time the button is pressed.

Undervoltage cutout
At low engine speeds (up to 1500 rpm), the charge status can be turned negative as the result of high loads. For this reason, the rear-window defroster relay is switched off when terminal 30 drops below 11.4 V. The rear window relay switches on again when a voltage above 12.2 V is detected.