Planet Minis

01s4

I solved my first problem of wiring the tail light (1972 CT70) after finding out that the grounds were bad. I used the ground off the battery harness as the ground for the tail light. The power source for the tail light and brake light switch are the same, which was a red wire with a two point connector. I tried grounding the brake like switch to the same place as the tail light which then kills the engine when the brake is depressed.
So how should I wire this tail light and brake switch. I have been using the ground on the four prong battery connector. I am not sure exactly how to wire it and the diagram has not helped much. If anyone could walk me through how the wires should be set up I would be very grateful. Thanks