Hard to say what started this but here is what you do to prevent damage
1...One / some wires tend to melt inside the harness sometimes far away from "where you see" So you are going to want to 'plan' on tearing the dash and engine bay harnesses out, untaping them and inspect for "meltage."
2...When troubleshooting "in the car live" protect the system. There are LOTS of circuits in these girls that are not fuse protected. The fuse link is not adequate protection. So round up an old head lamp or tail/ stop lamp socket. Wire the two tail / stop wires together and treat that as one connection. The shell of the lamp is your second connection. Wire this device in series with the battery ground. With everything "off" (don't forget trunk lamp, dome, etc) it should not light. If you encounter a short as you are troubleshooting, your test lamp device will limit current flow, and not melt wires or blow fuses. The worst that will happen is the lamp will light
Obviously you cannot operate the starter with this rig
