Blinker / Turn signal doesn't work

[Wathakes]

Back right blinks fast and front right not at all. I found the manuals and attempted to make sense of them in order to avoid removing everything in order to manually trace the wire. But I have not been able to locate the connection or find resources that clearly show or explain where the bad wire(s) might be.
Since everything works except that blinker (and, consequently, the rear blinker going fast), it seems that it is a wire going directly to the bulb or something close to it.
Thank you.

[VStar650CL]

Here's a look at the Chassis Harness. The blinker circuit runs under the truck from Main to Chassis at C1, then across the truck to C15-C200 wire-to-wire, then to the taillamp. The C1 connectors are very infamous for water intrusion, so the first thing to do is crack it open and look for water or green pins. It's located on the outboard side of the righthand frame rail under the passenger door.