Motorcycle Questions? Ask a Mechanic.
Hi, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.Initially and if have not been tried; inspect the battery, its ground lines and/or check/clean the battery cables + terminals, connectors and wiring as a preliminary consideration.
Equally important, have the battery externally charged and then LOAD TESTed (even if new/charged and just for the purpose of eliminating it as a suspect).
All other tests would require the use of a volt/multi-meter.