I haven't seen a schematic either. There are probably individual circuit breakers that automatically reset, rather than a fuse block.
First, take the cover off the light that works, and with it lit, trace the wire out of the light housing to where the connector is. Note the wire number on the little metal tag on the wire. Then go to the side that doesn't work, find the same wire number, disconnect from the light, and check to see if there is 24v on that circuit with your test light. Use a test light rather than a multimeter, as a meter can show that you have 24vdc, but you may not have enough amperage available on the circuit to light the bulb.
One time on my deuce, the contacts in the turn signal lever weren't making good contact. It would light up real dim but not enough to flash.
Then trace the wire back if you can if it doesn't light up.
If you don't have a 24v test light, go to Napa, buy a 12vdc one, and change out the bulb. They have the bulbs that will work.
