Cool LED Tail Light Mod

[bruuuuce]

Well I had hoped to post this as a working mod to my 800... But I don't think I can figure it out on my own. Maybe someone here can help me. My problem is with the way Bomb has the rear tail light wired.



Here are pictures of the stock tail light.

Stock Off

Stock Tail Light

Stock Brake light



I found an LED light on Ebay and ordered it. I have it installed and now comes the wiring.

LED Off

LED Tail Light

LED Stop Light

Here is my problem coming from the wiring loom you have black, red and White... Black is 12 volts when the key is on and never changes. The white and red never get voltage applied. I am not 100% sure but to get the BRAKE light to work I had to wire the brp black to the LED red (stop light) and the BRP white to the LED ground. this makes the brake light work as it should. However hooking the BRP red up to the LED tail wire it causes it to all stop working.

So I get the idea to wire it as above without the BRP red, I disconnect it from the plug and tap into the starter selonoid (bottom wire only hot when key is on) and run it to the plug where the red was and wire it to the LED tail light wire. Turn the key on and nothing works, ground the white wireon the plug and now you can't tell the difference between tail light and stop light?

How do they have this wired? How can I wire up this led light to be bothtail and stop light?

[Kevin Z]

OK sounds like the LED will have to be modified

The Bomb switches the ground
From your description, this is what you have...
black is +12
white is brake ground (through the switch)
Red must be the switched ground from the lights.

Hook the (bomb black+) to the (LED red+)
Then the (bomb white gnd) on the (LED gnd)
When you apply the brake it supplies a ground to the LED, it is forward biased and the light comes on.

But....
The LED has a common ground.
When you hook the (bomb red gnd) to the (LED tail) your hooking a switched ground to the 12+ input to the tail LED, reverse biasing the whole thing. Hence it quits working.

You need to take the LED assembly apart.
Combine the 12+ brake and tail connections and bring it out as the 12+ common to hook to the (bomb black 12+)

Then in the LED split the ground from the Brake array and the ground from the Tail array and bring them out seperately to connect to the corresponding (bomb switched grounds)

There, clear as muddy water.

[bruuuuce]

WOW great explanation! Thanks for the schematic!



But I don't think the LED I picked is going to work in this case now. I am going to take it apart to make sure but it looks like the circuit board is epoxy coated.. I will have to find another LED light.



Thank you!

[Traxterman]

I like it I like it alot, I though of doing the same, but with dual lights , one on each side, sorta double the visibility thing.
Ralph:dan:

[Swampthing]

bruuuuce wrote:

Quote:

WOW great explanation! Thanks for the schematic!



But I don't think the LED I picked is going to work in this case now. I am going to take it apart to make sure but it looks like the circuit board is epoxy coated.. I will have to find another LED light.



Thank you!

How about one of those LED bulbs in the stock socket instead? No mods.

[bruuuuce]

maybe, but the bulb sits in the stock unit with the bulb facing up and to the left (11 oclock). I think the LED bulb would need to face directly out towards the lens to be effective.

[bruuuuce]

I tried taking the unit apart and it can't be done and save the light (i had an extra) it glued together and then expoxy coated. It was destroyed getting it apart.



the way I have it wired now would work (I think) I think I need to ad a resister to the led tail light circuit power feed. I think that would cut the voltage down to make the tail light portion dimmer so you could see the difference between the tail and brake. Just not sure if that will work I will have to try it. I am afraid the BRP white wire is causing the bright tail light and the resisoter won't do what I think it will.



Trail and error, it will be cool if I can get it to work though.

[Swampthing]

How about this-

[bruuuuce]

something like that would work, the base would have to be the traditional 1157 style base though. But the way the LED part is constructed would work.

[bruuuuce]

this might do it too