Electical problems, brake/tail light go out

Basic info: 2014 F800 GS Adv, 60,000 k on it, currently traveling Bulgaria, Tail light and Brake light quit working and panel indicated "Lamp".  I went into it and found I was not getting any voltage to the tail light assembly, but then once when I turned it on there was voltage. Worked on it for three hours could not find anything disconnected or otherwise wrong. Gave up, put it back together and ran 12k down the road to buy food, came back pulled in to parking and the lights were working??? Next morning I headed out with lights working, stopped and got fuel, started bike -- no tail/brake lights. 50 k down the road I get the idea to stop, let sit a minute and re-start -- now I have lights. 60 k further they go off again. The sometimes works, sometimes don't are the hardest electrical problems to find and I am stumped.
I recall hearing a while back about a problem with the wiring in or around the goose neck, was this on the F bikes, could this be the problem, shorting out and system shutting off power to the back?
Any help most appreciated
Bob
:ricky: