Have you had this bike since new?
If not, then a previous owner may have used something like a Scotchlok (spit) connector on the feeder wires to power aux lights. Unlikely but a possibility, even if it didn't work!
So, take a close look at the wires from the bulb connector into the loom as far as you can see! It isn't unknown for wires that have been Scotchlok'd to break once the connector is removed.