Motorcycle Repair: Electrical, filament bulb, dual filament

Question
Taillight stays lit like i have the brakes on. Using a tombstone taillight with an 1157 dual filament bulb. I have no turn signals ( removed them ) just cant figure out the wiring for this thing. There is a wiring harness which has two green, one red, one purple, and one brown wire. There has definitely been some electrical creativity done before my fun began two days ago. I have pulled the bulb and socket out and tried every different combo of two wires to the light. No luck either half lit or brake and taillight both on without pressing either brake. Any help or suggestion of starting point of replacment would be appreciated. Thank you
91 Heritage Softtail
1st Guess is the two prong sending unit or relay inline with the brake line has a red wire on one prong and a orange wire on the other. Not sure if this is the problem.
2nd Guess major rewire job. Hate to do all that when i only have a tailight and a headlight.  

Answer
loosen up right controll switch housing and push it all the way in up aganist the brake lever mounting housing and hold it there an tighten the switch housing. it is not in the correct position and it is keeping your brake lite on.
www.southsidesdyno.com  602-340-1266 phoenix AZ
Southside Johnny