Welcome to NICO.
Have the chain guides been replaced?
If you don't know, now is the time to find out and replace if necessary.
Investing in a good automotive multimeter and learning how to use it will go along way in hunting down electrical gremlins.
I've only had the brake lamps squat on me so far.(Stop Lamp Out sensor went bad)
Here's an FSM to help
http://phatg20.net/modules.php...d=203