2009 Buell Ulysses Top Case Integrated Lighting

Functional schematic

Blue: running +12 V Red: brake +12 V Black: ground

Wiring schematic showing the two 1N5404 diodes and dimming resistor before the two-wire waterproof connector, with combined positive and ground continuing to the top-case LED assembly.

Connector / harness

Location	Wire	Function
Motorcycle loom	Blue	Running-light +12 V input
Motorcycle loom	Red	Brake-light +12 V input
Motorcycle loom	Black	Ground
2-wire connector	Positive	Combined dim/bright output
2-wire connector	Ground	Ground return to LED

The resistor and both diodes are in the motorcycle-side loom before the removable waterproof connector. Only positive and ground continue into the top case.

Operating logic

Condition	Current path	Result
Running only	D1 and R1	Dim
Brake applied	D2 bypasses R1	Bright
Both active	Brake branch dominates	Bright
Key off / no brake	No positive feed	Off

D1 and D2 are 1N5404 isolation diodes. R1 is believed to be 50 Ω and is known to fall between 10 and 100 Ω. Measure R1 if the loom is opened.

Installation photographs

Completed Buell top case with the integrated LED lamp illuminated — Completed lamp operating behind the factory top-case lens.

Open Buell top case showing the wire routed through the lid and hinge area — Inside the top case: lid entry point and wire routing.

Waterproof connector carrying combined positive output and ground to the top case — Waterproof connector: dual-level positive output and ground.

Two-wire top-case lighting connector installed beneath the rear bodywork — Two-wire connector installed beneath the rear bodywork.

Lighting cable entering the underside of the top case near the hinge — External cable routing and entry near the hinge.

Original 2016 fabrication showing two parallel LED strip runs behind the red reflector — Original January 2016 fabrication: two parallel LED-strip runs mounted behind the reflector.

Wrapped motorcycle-side lighting loom containing the resistor and diodes before the connector — Motorcycle-side loom: the dimming resistor and isolation diodes are upstream of the connector.