I purchased the undertail from Ebay. I wired the undertail last night but kept blowing fuses. What is the right way to wire it? The brake light/running lights from the undertail have three wires: Black, yellow, and red. I am assuming black is ground which i connect to green on bike. I played around with the other two, connecting them to the black or green with stripe on bike, but the fuses kept blowing.

 

Your best bet is to use a multimeter to verify which of the wires on the bike is actually the ground wire. If you do not know how to use one here is a good link to a tutorial on multimeters.

http://mechatronics.mech.northwester...ultimeter.html

If you are near Atlanta I would be happy to assist you. If not just use the meter to locate the ground wire. Once you have found the bike side ground wire you can use the meter on the VDC setting to find out which wire is for the tail light and which one is for is for the brake light. If you get stuck let me know. I will try to help as much as possible.
T

 

here is the pic you tried to post:


on this board its [ /image ] (without spaces of course)

 

the yellow is for the turn signal and red is for the brake light, they share the black wire as a ground

I don't remember what color wires are what on the bike though, but I'll do some searching and get back to you

here we go, this should help found it on another site:

 

Quick update: I was playing around with the wires tonite. Here's my observation: I think one of my LED brake/running light is

broken. I was able to get one of them to work correctly as brake/running light; the other LED kept blowing a fuse. I used the same

wires to test each LED light seperately, and the bad one kept blowing a fuse, while the good worked right. On the bad one, if I leave

the running light wire disconneted, the brake light works fine. As soon as I connected the running wire, the fuse blew. My question:

It is possible for a bad LED to cause a fuse to blow? I know with regular bulbs, if it is broken, it just doesn't light up; no fuse would

pop.

 

well, if a bad led is blown, it CAN create an open circuit. So what prob happened is that the led is blown, and when you press the brakes, voltage is sent out, but then the voltage cannot go anywhere (suppose to be through the led and then to ground because the led is broken) So essentially, you're fuse keeps on blowing because it's doing its job, no letting any current/voltage through to where it cannot go to ground.

 

I am very confident the LED is broken, but wasn't sure if it would cause a short circuit. Can anyone please point me where I can purchase a replacement undertail LED like the one on the pic I posted earlier. The LED has three wires, black, yellow, and red. I was looking on Ebay last night, during the time i was searching, I was unable to find a replacement set. Thanks again.

 

Not to say your wrong or anything... but your wrong.. lol you have somewhat of the right idea but are somewhat missinformed. a blown led can create a open circuit or a short circuit. thing being if it created a open circuit it would simply not light. a fuse blows when there is too much current drawn. so if there was a short circuit where you went right to the ground source it would heat up quickly and pop the fuse. LED (light Emmitting Diodes) are one way. if you hooked it up backwards (swapped the ground and power) you will ruin the LED. current can only pass one way through them and if you try the other way you will ruin the LED. so that is probably your problem. The wire stated above is correct, and you are correct to say it sounds like its the LED that is the problem. but if you havent hooked it up backwards it is somewhat unlikely.. could also be the socket . if that is shorted out then it would blow fuses. swap the bulbs and see what happens. if the other bulb lights in that socket its the bulb thats bad. if the other light doesnt light and it still blows the fuse then its a bad socket.

 

That lense should come off and it should be a normal automotive LED bulb behind it. you can get them at autozone, advanced auto, or whatever local auto store you have around you.

If it is an entire unit contact the undertail company for replacements

 

Hey man, was the problem ever fixed? I'm having the EXACT same problem with my fuse blowing. Could use some help man.