2006 Yamaha Vstar custom starter issue

on a Harley your starter solinoid is bad, on yamaha not sure

If the starter relay is working properly after you install the fully charged battery, and that means engaging when you hit the button, then there's no reason to replace it. Unless you just want to replace it with something better.

The starter button is used in an open circuit design.
You must press the starter button to "Close" this circuit before the starter will engage. Taking the starter button out of the loop helps support the suspect short. Assuming you kept the starter button wires from touching. :) If not, it is most likely the starter button.

Trace the wires coming from the starter button.
There could be a short circuit. (Same as pushing the starter button). Check along the handle bars and anywhere rubbing could cause a break in the insulation. Try this at night with the lights off.
You may be able to SEE the spark and locate it quickly.

Good luck!

Could be a starter issue, or a wiring issue. Check for power at the starter when the button is pressed. If you have power, you need a starter, if not, trouble shoot the electrical system.