Short problem small block

Hi everybody.

First let me tell you that all of the ignition is pei and new but the wiring is probably as old as the 69 Dart, It was working just fine though until I went to go start it a few months ago. Lots of head lights but just a click for the starter then the lights went out. I went out and played around with the battery cables and same thing. Lots of lights then when I try to start it..click then the lights are dead. The battery is good. It's a 318.