Hi all. I've done some searching and couldn't find an answer, but my apologies if this has been covered in a previous thread I may have overlooked. Here's the deal...
With the original tach, any time RPMs went above 6k or so, regardless of which gear it was in, the needle would gradually float back and forth between the actual RPM and roughly 500 RPM lower. Once they were back below 6k, the needle would function as normal. Sometimes if I accelerated hard at high RPMs it would take a second for the needle to move at all, but this was a random and relatively rare occurrence.
Recently I found another K75 instrument cluster in much better shape all around than my original for about $20, so I swapped it out. Since then, the new tach will operate fine until the bike heats up, then it is constantly swinging between 0- 5k and back, totally independent of what the real RPMs might be. Once this starts, it doesn't matter how low or high the actual RPMs are, and it continues even upon restarting if the bike is turned off for a minute (again, seems to persist for as long as the engine is warm). Speedometer, odometer, trip, and instrument lights all work fine while this is going on.
So here's the weird part that may or may not be related. When I bought the bike it had no turn signals. The brake light was out, and the fuse was blown (2nd from top if I remember correctly). So I added turn signals I had laying around using the original wiring: 2 regular at the rear, and 2 LED at the front. Then replaced the rear brake light and the fuse and was surprised that everything worked without additional resistors to trick the indicator circuit. Everything worked as it should for about a month, until suddenly the left signal would randomly fail. I also noticed the horn sounded weaker as well when this happened. Further adding the the wackiness... when the signal fails, I can generally switch on the right signal, cancel it, hit the horn, then switch on the left signal, and the left will suddenly work again. :dunno2: Sometimes (but not always) just honking will make the left signal kick in, and you can hear the horn suddenly get louder when it does. I couldn't find any discrepancies in the wiring diagram, and checked for bad grounds and found nothing. Any chance auto-cancelling feature could have something to do with this?
I read something somewhere that made it sound like there might be a correlation between a flakey turn signal and a bouncy tach, but it never elaborated or clarified how. If I'm honest, sorting out electrical problems isn't exactly my strongest suit, so any help, hints, or guesses about all or some of what's going on here would be greatly appreciated.
