The magic blinkers (are THESE the ones?) have been working for two years, so they're probably not the root cause of the problem. Sounds like a connection issue to me.
Do the lights fail after any particular set of circumstances? Riding in the rain? Bumpy road? After a long day on the road? If so, it's almost certainly a connection issue. It probably wouldn't take you even a half hour to re-do all of the connections, have a minimal cost for some fresh solder/connectors, and it certainly won't hurt anything. Look for little scorch marks while you're doing the job; if you find them at a connection point, then that's the one.
And if it isn't, just looking closely inside there may well reveal the real problem.
Do the lights fail after any particular set of circumstances? Riding in the rain? Bumpy road? After a long day on the road? If so, it's almost certainly a connection issue. It probably wouldn't take you even a half hour to re-do all of the connections, have a minimal cost for some fresh solder/connectors, and it certainly won't hurt anything. Look for little scorch marks while you're doing the job; if you find them at a connection point, then that's the one.
And if it isn't, just looking closely inside there may well reveal the real problem.