So today my tail lights finally gave up as they won't come on when the headlights are. They only come on when I engage the front or rear break, I checked the bulb filament, fuses and any connections I could get my hands on but to no avail. I had problems for a while where the tail lights only had one working light for a while then sometimes both lights would come on but now the both of them are off :-/ My ideas are there's a fault in the control handle which houses the light switch, a wire is badly grounded, connections are bad somewhere, maybe a faulty relay? Has anybody got any experience with a similar problem?
Just as I was about to put the bike back into my shed one of the park lights came back on when I was putting my bulb back into its socket, turns out the culprit might be bad connections in the bulbs socket. I checked the other bulb that failed to turn on and the filament has blown so the connections in the socket must be bad :-/ Thankfully I've found the problem I HOPE ;-)
Try spraying the bulb holder with wd40. And see if the base is moving freely so it can make full contact