I recently had my left rear blinker drown in a puddle while dual sporting. I found a loose connection on the right panel (white tab) and reconnected it, checked fuses, wiggled cables there and under rear fender. Still the left rear blinker is not working. The housing was cracked and the bulb was broken. I replaced the bulb. Still haven't taken the seat off to check cables yet? Any suggestions?
Disconnect blinker and test with an ohm meter, also test bulb with meter to make sure it is good. I'm betting that something is broken in the socket itself, the meter will verify it (or not) but this would be a good place to start.
2013 Yamaha TW200
1996 Yamaha TW200
1995 Kawasaki KLR650
2002 Yamaha RoadStar 1600 with sidecar
From corrosion visible on broken bulb I would expect to see similar white gook inside socket . Clean any corrosion inside socket and socket terminals. Check socket's ground and hot terminals with ohm meter if replaced bulb still doesn't illuminate.
Had a neighbor's landlord help me today. He started playing with the cable hookups under the read fender and the turn signal now works! Might have been a loose connection or moisture issue.