A problem for many older bikes and even the newer ones is the main circuit breaker that powers the bike.
They get tired with age and loads and will trip earlier than they should at times when loaded.
The heat of the engine and it's location will also have an effect on it too and trip it earlier than it should leaving you with no lights and on some bikes no electric at all. It will usually reset after a brief cooling off period.
It's a cheap part and can be bought at any auto parts store as long as it is the same physical dimensions and amperage as the one you removed.
The later baggers even upped the amperage of the breakers for a similar problem by 10 amps to a 50 amp breaker.
They get tired with age and loads and will trip earlier than they should at times when loaded.
The heat of the engine and it's location will also have an effect on it too and trip it earlier than it should leaving you with no lights and on some bikes no electric at all. It will usually reset after a brief cooling off period.
It's a cheap part and can be bought at any auto parts store as long as it is the same physical dimensions and amperage as the one you removed.
The later baggers even upped the amperage of the breakers for a similar problem by 10 amps to a 50 amp breaker.