PROJEKT36 · WIRING

Towbar, phone & parked ventilation

Factory option circuits: the 13-pin trailer socket, the telephone connector and cradle, and the parked ventilation relay. Hover or tap a row to see where the wire goes.

Standard petrol E36 from the 1998 BMW wiring manual. On a phone, scroll the diagram sideways.

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SW blackRT redGN greenBL blueGE yellowBR brownWS white GN/SW = green with black stripe supply / ground of a part shown elsewhere

Trailer socket

0.75 BL/GN turn signal circuit, splice X313 0.75 BL/BR turn signal circuit, splice X314 1 GE/WS fog light circuit, splice X1214 1.5 BL/RT brake light circuit / X1075 pin 7 0.75 GR/VI park light circuit / X1075 pin 5 0.75 GR/GE park light circuit / X1075 pin 3 0.75 BL/GE reversing light circuit, splice X428 2.5 RT/GR fuse F2 15A 2.5 BR ground X13006 2.5 BR ground X13006 X630 Trailer socket trailer socket, 13-pin 1 Left turn signal 4 Right turn signal 2 Rear fog light 6 Brake lights (54) 7 Left tail light (58L) 5 Right tail light (58R) 8 Reversing light 9 Permanent + (30) 3 Ground 13 Ground (pins 9–12)

How it works

The towbar socket takes its lamp signals from splices in the rear light circuits; with check control the brake and tail feeds come from the check control module so the trailer bulbs are monitored too.

Redrawn from BMW ETM 6328.1 (05/99), standard petrol E36 (316i–328i); diesel and M3 parts are left out. Not covered: pins 10–12 are not wired from the factory.

Cellular telephone provisions

fuse F33 fuse F43 ground X13006 0.5 WS/BR radio X18126 pin 4 0.5 GR/RT light switch 58g 0.5 SW/WS cluster X17 pin 2 ground X10012 X400 Telephone provisions telephone connector, boot 1 Battery (30) 5 Radio position (R) 2 Ground 6 Radio mute A117·5 Cradle lighting A117·2 Road speed A117·10 Cradle ground

How it works

Cars prepared for a phone have a connector in the boot with permanent and radio-position feeds, ground and the radio mute line, plus the eject box (cradle) in the console.

Redrawn from BMW ETM 6561.0 (05/99), standard petrol E36 (316i–328i); diesel and M3 parts are left out.

Parked (independent) ventilation

2.5 RT/GN fuse F20 30A 2.5 RT/GN fuse F20 30A 0.5 SW/WS/GE on-board computer X1071 pin 14 2.5 GN IHKA X1527 pin 20, splice X10103 2.5 GN blower resistor X999 pin 1 K450 Ventilation relay independent ventilation relay, X607 2 Contact supply 8 Coil supply 4 Coil ground (timer) 6 Blower feed (IHKA) 5 Blower feed (HR)

How it works

Parked ventilation runs the blower with the engine off, on the on-board computer's timer. The computer grounds relay K450, which feeds the blower from F20 around the normal blower switch.

Check on your car

  • With IHKA, the ignition line to the blower relay K4 gets decoupling diode V6 (X1405 / X1406) so the parked-ventilation feed cannot back-feed terminal 15.

Redrawn from BMW ETM 6412.10 and 6412.20 (05/99), standard petrol E36 (316i–328i); diesel and M3 parts are left out.

Reading the wire codes

BMW labels every wire with its size and colour, for example 2.5 SW/GE: 2.5 mm², black (schwarz) with a yellow (gelb) stripe. Connectors are numbered X…, followed by the pin. The wires in these diagrams are drawn at relative thickness, so the 25 mm² battery cable stands out from a 0.35 mm² signal wire.

Codes used here: SW = black, RT = red, GN = green, BL = blue, GE = yellow, BR = brown, WS = white.