Wiring Color Codes

  • by Airhead Contributer

    • Wiring Color Codes

    This covers most of the basic wire colors used on Airheads.  As the electronics got more complex, more combinations came into play so it’s possible a few of the more obscure ones may see other uses.  Always double check factory wiring diagrams, and yes, even they can have a mistake or two.  PowerBoxer.de has a copy of the Haynes ones. And here’s a link for more about Airhead relays and terminal designations.

    !!! NOTE !!!

    It was common practice to substitute a different wire color if the proper one was out of stock, and then “flag” it with the proper color(s).  As the flags’ adhesive ages, it dries up and the flags often slide down the wire out of sight or fall off.  If you have an ‘odd’ wire, identify it through process of elimination by doing all others first, double checking with a volt/ohm meter, and then “re-flagging” it with the proper color. Better still, use heat shrink tubing of the proper color. ! ALSO ! Some books accidentally transpose numbers or letters on wiring diagrams (e.g. SW instead of WS, or two 86 terminals instead of a 85 and a 86).

    1. Wiring Key
    2. Main Wire Colors
    3. Lights’ Wire Colors
    4. Switch Wire Colors

    Most common . . .

    Still essentially universal among BMWs . . .

    For Airheads . . .

    Think you’ve got it? . . .

    – – – – – – – TEXT ONLY VERSION – – – – – – –

    RT = Rot, red

    GE = Gelb, yellow

    GN = Grün, green

    BL = Blau, blue

    VI = Violet, purple

    GR = Grau, grey

    BR = Braun, brown

    WS = Weiss, white

    SW = Schwarz, black

    xx/yy = xx wire’s main color with yy stripe

    MAIN Wire Colors

    RT — POSITIVE straight from battery, power to ignition key and starter relay

    BR — direct to GROUND

    GN — (+) power to most circuits

    GR — (+) power to PARK lights (head, tail, dash, …)

    GN/SW or GR/SW — same as GN or GR but it’s after the 8-amp FUSE

    LIGHTS’ Wire Colors

    GE — to LOW beam filament

    WS — to HIGH beam filament

    GE/WS — power to HI/LO switch

    BL/RT — LEFT turn signals

    BL/SW — RIGHT turn signals

    GR/SW — TAIL (as above)

    GN/RT — BRAKE light

    SW/WS — turn signal DASH INDICATOR

    BL — D+ from diode board and voltage regulator for GEN light

    BR/SW — NEU light

    BR/GN — OIL light

    BR/BL — BREMSE / BRAKE FLUID light

    WS — HIGH BEAM indicator

    GR/SW — gauge illumination

    SWITCH Wire Colors

    BR/?? — wire to SWITCH that completes path TO GROUND

    BR/GE — CLUTCH switch

    BR/SW — NEUTRAL switch

    BR/GN — OIL PRESSURE switch

    BR/WS — to HORNs with grounded bodies

    BR/BL — BRAKE FLUID switch

    GN/BL — engine CUT-OFF/KILL switch that supplies power to ignition coils

    BL/GE — to ground winding of STARTER RELAY

    GN/VI — trigger for HEADLIGHT RELAY

    GN/GE — TURN SIGNAL relay OUTPUT

    Please email me (see “Contacts” under KS A/M) with any comments or suggestions. Thanks! –Joe

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