Warm ignition switch

"What Tooljunkie said."
I had the same issue this evening. I'm restoring my 65 /6 Barracuda. Although It's stripped down, I have left the engine and drive train operational, as I move the car in and out of my carport to work on it. I noticed tonight (after moving the harness up out of the way of what I'm doing) that the grey wire (ignition 1) on the ignition switch connector has gotten "REAL" hot at one time (partially melted insulation) and the terminal was loose in the plug. That will absolutely cause a resistance problem, resulting in wires and connectors getting hot. I'm not having much luck getting the terminal out of the plug, some distortion is the problem. Once I get it out, I'll replace the terminal and the damaged wire.
Norm