Aftermarket Tail Light Wiring

Hi,

I didn't get much of a repose on the technical forum about this so I'm thinking this place would be a bit better for after market parts help.

I'm having difficulty wiring up an aftermarket tail light that the previous owner had hacked on the bike. The light itself worked but wouldn't get brighter when I activated the front or rear brake and the wiring was a complete hack job.

From looking on ebay I figured out it was the light below.

Looking at the wiring diagram I'm not able to make it work.. I have a cut up harness going to the tail light which is blue/yellow/black. I figured I did TAIL - Black to HARNESS Black, Tail Yellow to Harness Blue, Tail Red to Harness Yellow running to the brake light switch.. having no luck. Any idea why I'm not getting any light at all?

 

try black from the light to the bike frame. leave the others as they are.
if that doesn't work, test your light from a battery, prove it works

 

So I used another tail light to test and I am getting power. I can get it to light up with constant power from the keys. Now the problem I am having is that the brake light, which is supposed to be activated by applying the brakes is constantly on.. even when I disconnect the front stop lamp switch completely it's still getting power.. in my understanding the front stop lamp switch should be in line with the yellow wire and the light should not light up at all if the switch is disconnected in the headlight.. What am I getting wrong? Could it be the rear stop lamp switch that's the problem letting power through all the time?

 

Check that the rear brake switch isn't stuck on.

 

How did you disconnect the front brake light switch - are you sure it's disengaged - the little push button can get stuck. What happens when you disconnect the red wire? Do you have the ground connecting to a black wire on the harness or to the frame right now?

 

Could be the two hot leads are inadvertently reversed.

Could also be the bulb is 180 degrees off.

Could also be a defective bulb

Been through these scenarios enough

 

It was actually the rear brake light switch that was stuck on. I think the PO might have screwed around with the whole rear brake pedal assembly because the whole brake pedal goes up about half way up the cover : as seen on this picture:



I haven't had a chance to look at it.. the rear brake works but it's really soft and I had just put new shoes in. The way it is now, the spring was pulling the brake light on and wouldn't go back up high enough to disengage the switch while the larger spring that returns that rear brake was on. I'll have to figure out the proper way that whole assembly should be put together so it comes back down and can disengage the switch properly.

 

The rear brake will need time to bed in to the drum.
Where the peal sits in the photo is about right, but the arm on the drum should be canted back a bit more. There is supposed to be a spring on the pedal, near the swing arm mount, that pulls it back into place.

 

So in that picture, with the spring you're talking about that is where the pedal sits. However, when I take off the spring, I can lift that pedal all the way up to the top of that big scratch you see in the picture. Where it sits now, the only thing preventing it from going higher is the fact that it's hitting the cover however I can pry it up. Should it be able to rotate that far up with the spring taken off?

 

There is supposed to be a tab on the brake pedal shaft that prevents the pedal from going up that far.

Part #29 http://www.yamahapartsnation.com/oemparts/a/yam/500421daf8700209bc78740a/stand-footrest

Is the pedal pinch bolt in place, and are the pedal and pedal shaft splines in good condition?

 

I'll double check when I get home. I had a spare pedal shaft splines I had gotten when I replaced the long shaft that goes to the rear lever. The little screw (#40 in your link) only hits the pedal when it's at the upper position of that scratch as well. That's why I have a feeling the pedal might just be at the wrong place on the shaft. . That still wouldn't really explain why the spring for the brake light is too far down, might just need to adjust the switch. I'll take pictures when I get home to better describe the problem and hopefully find a solution so I can get back to riding!