Tried doing the same thing on my GS LC-- the can bus kept tripping with lights and nav on at the same time. They are led lights and draw 1 amp combined so it looks like bmw only intend the nav connector to power the nav. I never had any issues on my 2005 rt with the same lights and nav combo so assumed the gs connection would do the job. I thought it was a 5amp max feed but a 55watt bulb(4.5 amps approx) tripped it but a 21watt brake light bulb(less than 2amps) was okay.
Ended up connecting the nav only, using the 3wire connector. Theclights are fed from an inline bmw adaptor that goes to the back of the aux socket next to the clocks. Spliced the lights into the adaptor wire si the bike loom is not damaged. Good result because it is canbus protected znd switches off, after a small delay, when the ignition is off.
