Use a multi meter set to test continuity, blue wire should be brake light, yellow wire back light and black is earth. Touch one probe from your meter to the blue wire and touch the other probe to the black wire and press rear brake pedal and your meter should bleep, that means the brake Light circuit is fine, next with your lights switched on at the handle bar switch, touch one probe to the yellow wire at the back light and the other probe to the black wire, if your meter beeps the rear light circuit should be fine.
Last Edit: Jan 13, 2018 18:04:31 GMT 1 by mijapxman
I am also going to put tunnel rear lights on my bike. I am very interested in how you are going to go about this? I cant find anything on the internet apart from photos of the finished article. Any pointers would be greatly appreciated. Sorry for taking over the thread. I am using the SIP tunnel light kit which I purchased second hand. Regards