Addmotor M-430 lights stopped working

[Larry Mac]

I have an Addmotor M-430 ebike purchased about 15 months ago.
The front and rear lights suddenly stopped working although the controller shows they are turned on. (The brake light still works.)
Any suggestions on how to troubleshoot this problem?
Addmotor offered no assistance since the bike is out of warranty.

 

[tomjasz]

Check bulb first and then wiring continuity. We should all have a multimeter. Handy for sorting many issues.