I had that harness on my '70 Bee. The pigtail goes to cavity Z of the headlight harness, and the dash light wire to the same on the inside bulkhead connection. The Violet ground wire bolts to the dash frame.
The harness from the B/U light switch goes to the top left cavities of the wiper motor harness. Mine had a 2 wire pigtail coming out of cavites C and D, D being the hot wire I believe. The inside white wire is the power, it comes from the radio red connection, and the white w/ 2 black tracers runs to the body connector back to rear lamp harness.