Not wishing to ‘pollute’ OP thread I will start a new one. I noticed in another thread regarding an apparent electrical issue Wobbly asked if there was a headlight modulator installed. As I have one installed I am curious if these devices are known failure points. As an aside, mine has worked fine but since installing LED headlight I have it disabled as the reduced resistance makes it almost like a laser strobe and I am concerned regarding safety to oncoming drivers.
I asked that to make sure there wasn't a possibility of weird impulses being imparted to that particular electrical system that might be cooking the electronic voltage regulators. That particular poster had mysterious VR results after the bike had been running for awhile, so I simply took a stab. That was the background on that question.
My brother is still using the modulator that he first fitted in the mid-70's. Now it's mounted on his third motorcycle. I move them around myself. So I'd have to say that they are NOT a known failure point. In fact I've never heard of any issues stemming from their use.