As ridiculous as this may sound, using a multi-meter, are you getting any volts and the headlight plug(s)? Have you tried a new bulb? Put the multi-meter in the OHM setting, and touch each probe to the two prongs on the light bulb. If you get an OHM reading then the bulb is good. If no OHM reading, the bulb is bad.
Not likely that all headlights would blow at the same time, but if there was an electrical surge somewhere in the system, and the headlight switch was in the on position, then it could zap all the bulbs.
Start tracing it back. use a multi-meter, and test the headlight plugs. If there is no voltage there, then test the wires at the handlebar switch. If there is no voltage there, then keep tracing the wires back to either where they have voltage, or where they originate from to find the issue.
Are the taillights working when you flip the switch? Does the tail light work when you press the brake on the handlebar?
Last edited by Sti1471; 09-20-2019 at 07:34 AM.