I have a 66 Mustang coupe straight-six. I am in the process of trying to make a reliable daily driver. It was running great until a couple days ago. Now it won't start. When I turn the key, absolutely nothing happens. All the lights and turn signals work. The starter is good the solenoid is brand new. I cleaned all the connections to the solenoid, starter, and battery. I was told it might be a bad ground, but I checked the cable and it is in perfect condition. I took the ignition switch out and messed with the wires thinking it might be a loose connection, but that didn't work either. The battery is fully charged. The only thing I can think of is a short somewhere near the ignition switch. This seemed to happen when the weather got really hot and humid. Any advice will be greatly appreciated.