E24 Rear Window Defroster
K9 Illumination Control Relay
K10 Defroster Time Relay
S13 Defroster Switch
S14 Illumination Control Switch
Illumination control relay K9 controls the lightness of location indicator lamps on the IP and each switch according to the signal voltage of illumination control switch S14. All lamps connected to the 31b terminal of the illumination control relay should be routed to the ground only through the illumination control relay. That is, the current from the relay 31b to 31 (ground) is controlled.
The resistance between the illumination control switch terminal 2 and 3 is about 9 kOhm. It is constant at any switch location. When the light switch is operated, the illumination control relay 58b terminal generals about 5V and 58c terminal is connected to the ground through the inner relay. The signal voltage of the illumination control relay 58a terminal changes according to the switch position (the most light position is 5V, the most dark position is 0V)
The defroster switch S13 is a one touch type. That it, when it operates one time, the defroster time relay K10 is "ON" and the time relay operates for 10 minutes to be OFF automatically. If re-operating the switch during operating (within 10 minutes), the defroster time relay is OFF.