Your best bet is to take the bulbs out of the indicators on the left side, including the side repeater, then remove ALL fuses, now hook up a test light to the front indicator that you can see as you put the fuses back in, as soon as you put back the fuse feeding the circuit that is feeding a live to the indicator line the test light will light up, note what the fuse is for as this will help narrowing it down.
tabetha