Good Morning HD community, new HD owner, used to ride Honda sport bikes, just bought an 03 Sporty 1200C anniversary with 2500 miles on it, put 1500 mi on it since with no issue until the other day i was riding at 70mph, tried to give it throttle and it started misfiring/sputtering, turn signals wouldnt stay on and the speedo/odometer was on the fritz. Now it will idle but as soon as i rev it seems like the vibration is causing the problems to get worse. Checked for codes on the odometer, clear, and fixed a connector under the tank that was partially melted, but the problems persist without the plug in, it seems to be just for the turn signals. Any help would be appreciated, trying to avoid a $400 diagnostic bill at Harley, as i am a DIY guy, only way to learn! Thanks

 

First thing to check on a problem like this, is BOTH ends of BOTH battery cables for a clean and tight connection. Loosen, inspect and re-tighten.

What does "on the fritz" mean, is it dead or erratic?

 

Make sure your battery is fully charged, then try testing your voltage regulator.

Stay off the throttle when you start her up and test the battery voltage with a mulitmeter set to DC. You should read a little over 12V @ idle. You should then see a voltage rise momentarily as you begin to increase RPMs, after which it should settle into a stable reading. That reading should be between 13.5 and 14.5 volts.

That'll be your problem if you're reading anything more or less...

 

Yep, sounds like it's not charging.

 

Based on the OP's description, he doesn't say anything about having a problem restarting/cranking the bike. Not having a working charging system isn't a problem until the battery gets too low to operate the electrical system, at which point the battery would be far too dead to crank the motor over.

 

Yup......this would definitely be my first guess......

 

Checked all battery connections, positive, negative, ground bolt to frame, a little corroded so i brushed them and put dielectric grease on them. But now i have no power at all when i turn the ignition on. Battery has juice, ran multimeter across terminals while off and it read 12.4 volts

 

And on the fritz was my turn signals not staying on, the speedo was jumping all over the place and the odometer was flashing in sync with the vibration of the motor, however the bike was still sporratic in firing as if the spark wasnt solid

 

Sounds like a crappy ground connection. Remove your main ground cable, both ends, thoroughly clean both ends, and mating surfaces, reattach ground.

Most erratic 12vdc problems I've run into, usually comes from a bad ground.
A faulty ground will do some crazy stuff with 12vdc. This may save you a lot of time chasing ghosts.

 

+1 - That's what I was getting at when I asked about the "on the fritz" speedo being dead vs erratic.

The symptoms are dead on for having a bad ground, and being that it's affecting the motor and well as electronics, it's likely battery cable (main power) related.

You might want to remove the negative cable from the ground stud on the motor case, remove the stud, clean off the threads and reinstall.
Also check the terminal connectors on the cable ends aren't corroded inside.