As I explained before it is a GND problem . I was having exactly the same problem with tail lights and direction lights. When I opened the covers I realized that only one line is ending in the housing from the main circuit. After some investigation, I found out that CM uses the bikes metal body and parts as GND and only one line from the battery. Buth there is a catch with tail lights: Tail lights housing is electrically isolated from the body! You can see that on the base of the housing. There are two rubbers. If you attach GND line to the body of the bike and not to the housing, you have no results. Try to find this pin on the upper right corner of the housing. There is where GND pin must end. D.