1. Test light to the ?
a. I can start at the taillight bulb socket and work backwards to the fuse box.
b. I can start with each component and check for 1)connector not connected. 2)wire out of connector. 3)short to ground. 4)component failure like a bad bulb or winker relay.
c. I can start from the batter to key switch to hot wire out to the next component like turn signal switch is where I end up.
2. I'm going to make ground off a winker bolt or chrome body.
a. I use a pair of adjustable pliers so I can touch the winker body and then touch frame or a good ground.
b. I want to find a hidden ground off the chrome parts so I do not leave a visible arc and/or damage the finish someone looks at the bike but never the bottom, right?
c. This is the quick and dirty so as not to make a wire with alligator clips I don't have. So say this is a fast ground [with hand-tool] once the key is on and the winker is turned R/L or I have the brake pedal on, now make a better ground with a bare handled tool.
3. Tools.
a. Ohm meter
b. Test light
c. Adjustable pliers for ground-work or alligator clips with a black and red wire to work power off the battery [with key off], ground-work, etc.
Test light:
1. Is power to the winker relay or this all in one box.
2. Is power on both sides of the fuse when handle point is touched at the fuse.
3. Is power to the one bulb socket brass bumper.
4. Is power from the test light to battery to the ground side of the bulb socket have integrity to ground or is the test light dead as in no wire connected from socket ground wire to ground.