Today I finished wiring the wingtip strobe system and the wingtip navigation lights. The strobes are powered by the control unit which is located under the rear seat. The nav lights are wired through a circuit breaker/switch at the dash.
I installed the power unit on a non-conducting platform mounted to the bottom of the rear seat. The power unit needed to be grounded, as did the shield wire in the strobe/nav light power cable.