1990 BMW 3 SERIES Workshop Manual

BK Black
BL Blue
BR BrownGE Yellow
GN Green
GR Green or GreyGY Grey
OR Orange
PK PinkR Red
RS Pink
RT RedSW Black
TN Tan
V VioletVI Violet
W WhiteWS White
Y Yellow
Body electrical systems 12•9
12
Colour codes bent or damaged. The actuator can be
checked by applying battery power
momentarily. A discernible click indicates
that the solenoid is operating properly.
21 Electric window system-
description and check
2
The electric window system operates the
electric motors mounted in the doors which
lower and raise the windows. The system
consists of the control switches, the motors,
window mechanisms (regulators) andassociated wiring. Removal of the motors and
regulators is described in Chapter 11.
Diagnosis is usually limited to simple
checks of the wiring connections and motors
for minor faults which can be easily repaired.
These include:
a) Check the electric window switches for
broken wires and loose connections.
b) Check the electric window fuse/and or
circuit breaker (where applicable).
c) Remove the door trim panel(s) and check
the electric window motor wires to see if
they’re loose or damaged. Inspect the
window mechanisms for damage which
could cause binding.
22 Wiring diagrams-
general information
Since it isn’t possible to include all wiring
diagrams for every model year covered by this
manual, the following diagrams are those that
are typical and most commonly needed.
Prior to checking any circuit, check the
fuses and circuit breakers to make sure they’re
in good condition. Make sure the battery is
fully charged and check the cable connections
(see Chapter 1). Make sure all connectors are
clean, with no broken or loose terminals.

12•10 Wiring diagrams
Typical starting, charging, horn, hazard flasher and direction indicators (1 of 4)

Wiring diagrams 12•11
12
Typical headlights/foglights and interior lights (2 of 4)

12•12 Wiring diagrams
Typical check control, electric mirrors, stop and parking light (3 of 4)

Wiring diagrams 12•13
12
Typical instrument cluster and cigar lighter (4 of 4)

12•14 Wiring diagrams
Typical Motronic system wiring diagram (1 of 2)

Wiring diagrams 12•15
12
Typical Motronic system wiring diagram (2 of 2)

12•16 Wiring diagrams
Key to Motronic engine control system wiring diagram
Key to cruise control system wiring diagram