check your test light using the battery to see if it lights up. No relay needed.
Black normally is ground. Red could be for break. The other is for running light.
Take test light and hook the one end to ground like frame. Now turn key on and see what wire has power.
Now tie break lever to grip so the break light should be on and see what wire has power.
Now with new light hold or clamp black white to the ground on battery. Now take the other two wires and one at a time touch to the positive side of battery. The brightest one will be break.
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