As part of our TR6 resto we were working to complete the wiring harness install. As soon as we touched the cable to the negative terminal we experienced a spark which suggested that somewhere we have a short circuit. So we methodically began to unplug to isolate the issue. We found that the brown wire connected the starter relay at C2 to the fuse box was the culprit. There was no spark at the negative terminal with that wire disconnected. My question is, what is disconnecting that wire telling me about where this short may be occurring. We can read the wiring diagram with an amateur's eye but need some direction where we might look to solve our issue. Thanks in advance for your input.