03 Ultra Classic developed a speedometer issue causing it to bounce erratically then eventually peg to 0. Also, the odometer wouldn’t register, cruise was non-operable, auto turn signal cancel didn’t work, and the bike would die or idle very slowly and rough when disengaging the clutch to stop. It would run fine for around 30 minutes then the problems showed up. I changed the speed sensor, transmission lube (crazy I know, but someone else said it worked for them and I was desperate), the breaker, checked the battery, inspected every ground and electrical connection I could find, and spent a good amount of money at Harley over 2 days letting them inspect It. According to Harley the bike was in good shape and they couldn’t find anything wrong with it. All signs pointed to an electrical gremlin until one day I happened upon a can of Seafoam at Autozone and said, why not? It does have a bothersome pop when rolling off the throttle, what could it hurt? Apparently the computer was being confused from the bike running lean causing an electrical disturbance resulting in my 6 month, $1200 nightmare. After 1 can of $8.99 Seafoam in the fuel the bike is running great without any issues. A can of fuel system cleaner is worth a shot to anyone having weird electrical issues that can’t be diagnosed. Honestly never ever would I have considered the fuel system to be the culprit of an electrical problem, but obviously that’s a real thing. Good luck, spread the word!