I've heard that noise, the flasher unit going mental, the switch had started playing up, pulled it apart and there is a sliding contact, spring mounted in another sliding block, that wasn't moving quite as far as it should, or stopping where it should. cleaned and freed up all that gear, still the noise, not as often. Pulled it apart again this time completely disassembled it ( It actually disassembled itself, luckily found the bits) and found the tiny brass contact that slides along the tabs in the switch had worn through and were not touching well enough to conduct properly. If tiny little spring loaded pieces of greasy plastic and brass aren't your thing, maybe just get a new switch. otherwise have a look, I just folded up a thin piece of brass shim, (piece of feeler gauge) to make a new one.
Also have three wires for the flasher unit, but only had two terminals on the unit itself. when I changed it for another with the three terminals, noticed that the flasher lit the moment I touched the switch as opposed to the two prong unit where the flasher only lit at the first click of the unit after I touched the switch.
The fault with the rear flasher may just have triggered the worn switch to start failing, bit more current to take another nip out of that brass contact.
I remember taking the other gauges off about twenty years ago and putting those ones on, not sure why, had a little fairing as well that I've never seen on any others, Wish I still had all those bits, It was only a tiny fairing with a short windscreen but made cruising so much more comfortable, louder as well, every tappet, chain, gear, induction noise reflected up under your chin.
Did a 14 hour day on it once, ears were ringing to the sound of timing chain at 4000 revs for hours afterwards.
Brisbane to Airlie Beach.
