engine turns over, will not fire

Hey guys, I need some help with the slant six. It's a 64 Dart GT and I had it running pretty good. Today I changed the oil and took it for a short ride. I started the car later and the engine stalled after a few seconds. Now it will not start. The engine turns over, bit it will not fire.

I changed the ballast resistor and it did not fix the problem. I took out one of the spark plug wires and cranked the engine and there was no spark. I did notice a wire that runs to the engine (see attached pic) that looks kind of weak near the connector. It is on the right side of the engine, rearward of the oil filter. I may have snagged it when changing the oil filter. Does anyone know what this wire is for? Would it cause an ignition issue? Any help would be appreciated.