So the bike is 02 low rider.
Recently installed MoonsMC led taillight.
also installed badlands load equalizer to remedy No flash/ hyperflash. The tailight works, intergrated signals work but the brake light DOES NOT. Neither the front brake lever or the rear pedal. BUT if I install the stock taillight the brake light works with no issues. I'm stumped. And I would appreciate any and all feedback. Thank you.

 

Test the light off the bike with a 12 volt power supply. The instruction should tell you what wire goes where. Test each one to make sure all segments of the light actually work. Ya got 1 of 2 problems here, ether new light is defective or it's not wired correctly.

 

The wire position on the tail light for the brake is not always positioned properly. Which wires are in the large 4 pin connector off the tail light?

 

Light Emitting Diodes are very finicky with polarity. Are the wires on that portion of the light transposed ?

 

Should be 5 wires in the plug. RT turn, LFT turn, running light, brake light and ground. Same on the new tail light. Bench test it.
Sometimes they push out and don't make contact.

 

An 02 would have three separate plugs on the light mount, one for the right, one for the left (both two pin) and a four pin for the brake (ground, brake, running, and unused). I don't know a tail light that comes with a connector to go straight to the wire harness, but maybe.