9-3 SE Sedan (9400) L4-2.0L Turbo (B204) HO (1999)
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Power Window Relay: Description and Operation
Window Lifts And Relays
The window lifts are operated from five switches located in the switch panel on the centre console. The switches are connected to the STC control
module, which activates the corresponding window lift relay to operate the electric motor for that window lift. The window lifts are driven by DC
motors, which change their direction of rotation by reversing the polarity of the motor terminals so that the window can be raised and lowered.
Each window lift has its own relay, which supplies the corresponding window lift motor. The relays are mounted in two relay holders behind the right
and left side trim.
The switch-over contacts of the relay, which control the direction of rotation of the window lift motor, are voltage fed on pin 1 on the front right/left
relay from pin 14 (22a) and on the rear right/left relay from fuse 7 (22a). Power ground is from pin 5 to grounding point G36 for the left front/rear relays
and grounding point G24 for the right front/rear relays. The integrated circuit is activated with +54 voltage to pin 2 on all the relays from fuse 21 (22a)
and is signal grounded via pin 6 on all the relays to grounding point G36.VR bus communication takes place on pin 8.
The STC control module controls the relays with the following messages on the VR bus:
