Jerry, I usually understand your advice but you have me on this one. How is a light in the fuse holder going to isolate a short to ground? Won't there be current flowing through the bulb whether the system is grounding through the turn signal bulb or grounding from a short?
I was trained to troubleshoot on military aircraft and I prefer to troubleshoot with a meter. I'd determine which side was blowing the fuse, left or right. There you've narrowed it down to two circuits. Disconnect the wires to that side and with your meter check for resistance. If there is significant resistance that circuit is grounding through the bulb. If there is little or no resistance it is shorting to ground.
