the first place i would look it battery terminals (remove, wire brush clean), then check all the earths are clean (use wire brush/sand paper), after that i'd be unplugging everything and making sure all connections are clean and dry.
Andrew

i had the speed sensor replaced under warranty on my 08 883C cause speedo stopped .... i think cause i use to have it outside in really cold adelaide hills winter before shed was built and moisture stuffed it up

ive noticed my indicators dont cancel some times and I get a slight stall after a minute or so when I 1st start her up

Same problem with my Sporty and for some reason I looked under rear mud guard and found the tyre has been eating the wiring . I"m glad my problem was fairly simple to fix, lets know what you find.