Rear Window Defroster Up to 11/99

Function prerequisites
Circuit 61 ON (engine running recognition)
Voltage not too low

Function
The rear window defroster can be switched on by pressing the rear window defroster switch (S21s9) in the center console. The switch contact connects the corresponding input of the all-activity module (AAM) (N10) to ground. The all-activity module (AAM) (N10) checks whether the function prerequisites are fulfilled and switches on relay F1k1. The rear window defroster indicator lamp (S21e2) in the rear window defroster switch (S21s9) is switched on parallel to the relay coil. Since the rear window defroster (R1) also functions as the radio antenna, it is connected to the antenna splitter (A2/5). The relay switches an input of the antenna splitter to circuit 30 via a fuse.

The all-activity module (AAM) (N10) switches the rear window defroster relay (F1k1) off when
the rear window defroster switch is pressed again, however at the latest after expiration of the delay time of 10 min.