Haha, I wanted to go with the VOM, but that gets too intense describing the procedure to troubleshoot with. For the record, my prefered method, is to identify which circuit at the fuse box, and disconnect the battery. Check continuity from fuse box to the mid-point of the wiring harness circuit that has the problem. Divide again till the problem is found. In this case, since it's a dead short, it's continuity between the frame (ground) and the wiring harness, since there shouldn't be any with the battery disconnected. Bulbs are a problem, they may have to be removed or unplugged, since they connect through to ground. But bulbs should show some resistance, and that can be seen and disregarded. Looking for VOM voltage (resistance/continuity) feeding the frame in any portion of the harness. Again, if wires move around, the short might go away temporarily. Sometimes have to resort to pushing pulling shaking wires to find the short. It's easier when it's a short with the key off. Since this is not, more than likely the trace will have to go through the ignition switch as well. I try to eliminate the ignition switch as a possible short, right away.