The front turns are also marker lights on all but '87 models. They carry 2-filament 1157 bulbs and have 3 wires. One filament is always "on" serving as marker lights, the other is for the turn signals.
The rears function only as turn signals (in fact it's illegal to have amber showing in the rear unless the light is coming from a turn signal). They have single filament 1156 bulbs,and two wires.
If you have anything else you have a wiring problem or some P.O. in the bike's history did something funky in the name of increasing "visibility".