my brake lights work...but my rear running lights wont. fuses are fine. battery is a little low but they would still come on when bike is on....i cant figure it out.....the three wires going to the tailight....one green one green and yellow and one black and brown.....only the black and brown one is hot....should one of the other ones be hot as well??....i have no idea where to turn next

 

If you're referring to your tail light there should always be one +12V hot wire to that all the time whenever the key is in the ON position. The other one is only hot when you apply the brake. The third one is the ground.

Check the bulb. It sounds like one of the two filaments is bad.

 

i checked the bulbs. grounds. wires. battery. fuses. .....everything....the wire is gettin low volts. but they would still come on no matter what right??

 

I initially got the impression that the tail light and brake light operate from the same bulb. If they are two different bulbs it would be easy to check the voltage across the terminals in the tail light socket to see if there is +12V. If everything is fine to that point the only thing left is a defective bulb.

If they operate off the same bulb you can still check the voltage at the socket; you just have to be more careful. Since you said the brake light works then that rules out a defective ground because they both use the same ground wire.

 

Helps if you tell us what bike you're referring to - I've got 6 different shop mauals on my PC here I could reference the wiring schematics. I have most of the taillight stuff memorized tho.

Since you mention the black/brown tells me you're prolly on a F4 or newer (that wire was solid brown on some earlier models). The Honda typical wiring - solid Green is always ground. In the brake light, the Green/Yellow is your stoplight function. Black/Brown is the running lights. the wire at the taillight is the exact same circuit that feeds the running light on your front markers as well.

Are the front running lights functioning? Any custom flushmounts, LEd bulbs anything like that?

You realize that taillight bulb has 2 filaments in it - low wattage filament for running light, and the other filament is for stop light. If you've lost the low wattage filament, that's the problem. In your harness for the taillight, if it is bullet-style connectors, swap the green/yellow and the black/brown. Now you should get the (bright) stop lights on all the time, and the dim lights would light up with break pedal/lever application.

Edit: I forgot to mention that the green/yellow stoplight circuit typically gets its voltage from the black/brown wire when the brake lever is depressed. The fact that the taillight is working properly, means that the black/brown circuit is functioning and energized, at least at the brake lever/pedal branches.

 

sorry for lack of info guys. its a cbr600f4i. i sat around all day yesterday and last night. and just figured it out this morning. somehow someway. the wiring in the bike was all redone (from the undertail kit) and done backwards. haha. a good multimeter was my success. i switched all the wires back to normal. blew a fuse. fixed that. got new bulbs and im back up and running! but thank you! i appreciate everything. this is my first bike and im sure ill be back for some more info =]