Just purchased a new tail light for my custom..The first thing I noticed was there were only 2 wires coming from the light..The old one had 3. Rear brake,running,and front brake light..I assume..tried jumping the 2 wires that went to the brake light side, but only the rear brake light works,and I do have a running light..The bulbs are 1156's also..thought they should be 1157's.. the place where I bought the light said most people only have the rear brake light set up and not the front..gee..thanks for all your help.. anyone have any ideas ??? Thanks

 

Mine was the same, the third wire is usually the ground. Bottom wire on the light is the running and the top is the brake, there's no difference on front or back brakes, they all work the same. I just ran the ground from the bike to the metal screw on the light

 

I'm not sure what a front brake light is. I have a model a light and it has two wires also. One wire is for the running light and the other is for the brake light. The ground comes from the plate mounting to the axle. I can't remember what colors go where, I just looked it up in the service manual and tested with the wires coming off the light.

 

Thanks JunkHead and Winchcable..I was thinking it may be a grounding issue..Had to do the same thing with the headlight I bought (run a seperate ground wire)..***UPDATE****just went to the garage and tried the ground wire solution..didn't work...hooked up the ground wire ? to one of the screws going into the light thru the plate frame..tried both screws and neither got the front brake to light up the light..the plate frame and light are powder coated..don't know if that has something to do with it..STUMPED !!!

 

If I remember correctly (and I do cause I just changed the turn signals on my King 57s in front 56s in back) the 1156s are single filament, in other words they're not wired for running lights and brake or turn signals just for brake or turn signal. The model A lights I had (off of our old model A) only had two wires one hot, one neutral(ground). If you need both functions youll have to replace the bulb mount in the housing.

 

You keep saying the front brake light, when you use either the front brake or the back brake they both light up the same light. Is the rear brake lighting up the light and not the front? If that's the case then you have the wires run wrong for the brakes. Really need some extra info on your bike to figure out what's wrong.

 

the rear brake is lighting the light and the front brake isn't..The tail light is also working...I also have a pair of LazerStar LED lights on the rear fender.They act as running lights,turn signals and brake lights. I ran the extra wire to the brake light wire on the new light.The fender lights lit when applying the front brake,but the new tail light didnt..I have checked every combination and still only get a brake light when applying the rear brake..Do you think it has something to do with the 1156's not being LED's ?? But why then would the light work when applying the rear brake and not the front ??? WTF !!!

 

Makes no sense, I'm stumped too, sorry man

 

The powdercoating on the frame and light don't conduct electricity very well, if at all. I had the same problem with a powdercoated passing lamp bar I put on my Road King this spring, no lights and strange connection problems. I sanded off some of the powdercoating in a small area where it mounts to the bike and all connection problems were solved.

Take the light/mount off the bike, remove a little powdercoating in an out of sight spot, attach an alligator clip to the bare metal and then to the battery (-) terminal. Run a wire from the wires on the light to the (+) terminal, one at a time and I'll bet you get a connection. The running light should be a little dim and when the full current gets to the brake wire, the light will much brighter. If that works, mark the running light and brake wires.

Good Luck.

 

Finally figured out the problem on the tail light issue..When tracing and checking the wires back to the brake light switch. I noticed an in line diode we had to use when installing the previous light set-up. I then realized I needed to run a LED bulb instead of a regular 1156 bulb..installed the LED buld and wha-la..it WORKED !!!