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Electrical Reference

Harley-Davidson

Common wire colors, fuse box locations, and relay tap points for Harley-Davidson motorcycles. Always verify with a multimeter before making connections.

Common Wire Colors

These are typical colors across recent Harley-Davidson models. Colors can vary between model years — always verify with a multimeter.

ColorFunction
BKGround (chassis)
RBattery positive (always hot)
BK/WIgnition accessory
VTurn signal left (rear)
BRTurn signal right (rear)
GN/WHorn circuit

Fuse Box

Sportster: under the left side cover. Softail/Touring: near the battery under the seat or side panel. Uses ATC blade fuses. Newer models (2018+) have CAN bus — avoid tapping CAN bus wires.

Relay Tap Points

  • Turn signals: V (left rear) and BR (right rear) at the rear fender connector
  • Horn: GN/W wire at the horn — usually behind the air cleaner
  • Ignition: BK/W at the ignition switch harness
  • Always-hot 12V: direct from battery posts (very accessible on Harleys)

Notes

  • Harleys have CAN bus wiring (2014+) — never cut or splice CAN wires
  • Plenty of space on most cruisers for mounting under the seat or in saddlebags
  • Battery access is easy — power connection is straightforward
  • Sportster models have the most limited space