Wiring LED brake lights in truggy project

[Bobby B.]

Well, we're getting going on a flatbed/truggy project for the Frontier. Pulled the bed and, to keep it street legal for the next few months, have welded up some flat steel fenders and a rear bumper. (Am going to make a utility/pseudo adventure style trailer out of the bed, but that's another story.)

Everything has gone well so far, but ran into an issue in wiring up the brake lights and wanted to sound off for a few ideas. We picked up a few round LED brake lights, generic looking, like for a trailer, but no matter what permutation of wiring they will not work. I've mapped out the wires/color codes from the FSM and each lights up the test light at the back of the truck. There are five wires at the plug.

The new lights feature three wires (black, white, green). There is no input on the packaging as to color coding or application. Popping them apart shows a circuit board and no fourth internal ground wire.

I've tried with the light bolted in (into steel), with a jumper wire to ground, running straight leads for brake and running to no avail. Has anyone used similar lights for a similar purpose who could offer what they did to have them function?

Thanks.

[CurleyMan]

Led's can only be wired one way - in other words your wires coming from the light are hooked up wrong. Re-attach them a couple different ways trust me they will work. Your ground wire is one of those three why would you need a fourth wire? Are you sure your not adding extra wires with the license plate lamp or reverse lamp? When I wired my LED the turn signals had both hazard and turn wires going to each lamp. For the red tail lights/stop lamps you should only have 1 ground 1 stop (brightest setting) and 1 marker light wire.

[Ryan Gee]

Mine was keeping beat like two rabbits humping. Used a trailer taillight adapter on them.

Used this one from Walmart on my HB, it works well.

http://webshareimage.com/images/hnukemktmi3c1sqa6y4w.jpg

[Bobby B.]

Ryan, thanks for the tip on the converter. Was wondering if I'd have to put something in to eliminate the ricer blinker syndrome.

Curleyman, I think my confusion is in how things are grounded. I think I probably had little or no proper ground and that's most of my problem. Perhaps I'm overthinking this, but I wasn't sure if the light itself received ground by bolting into the bumper, which case I'd have to run one of the factory harness wires to ground to complete the circuit?

I'm leaving the backup light wire alone for now, that's one down out of five. As far as the license plate light, the harness has a separate pair of wires out, so was going to splice into those.

That leaves four, one turn signal, one brake light, one running and one black, which I assumed was ground after examining the back of the factory tailight. If I connect the blacks for ground, that leaves three on the harness and two on the light. Do I then go one-to-one for the turn signal and slave the two remaining -- brake and running -- together?

Or is it like this? Black on factory harness to frame ground and the light grounds via its mount, then going one-to-one for the running, brake and turn signal lights?

Am going to futz around with this more later, am at work now and trying to see what I'm up against.

[soccerbrace]

I work with these every day. I believe it is the white which is ground. The others are tun, and stop. You need a second set for tails.

In my experience, some come stock with a wire which has a ring terminal. I think this is the white one. But that is always ground. If it has 3 wires, it is dual filament.

[soccerbrace]

The ricer burner syndrome is usually the symptom of a bad blinker on that side.

Oh and x2 on the one way to wire them. Since they are LED. the Diode part means it has a definite ground and + which cannot be reversed like on a Halogen. Additionally, you should use a test light for a computer. The computer test light will give you a green light if you tested the probe to ground, and have your ground on hot.

A sure fire way to wire an LED correctly though is just take it to your battery. Mess with it that way. When it turns on, you have the correct + and -. I am in the middle of a job where I am wiring my LED's in a series.

[Ryan Gee]

The ricer burner syndrome is usually the symptom of a bad blinker on that side.

Or a light with a different resistance.....

[CurleyMan]

no buy a two wire blinker led light. It will flash like it's high on BFE kitchen crack. You need to wire in a resistor to calm the neurotic blinker down. The LED does not ground automatically so find it's ground wire and two hot wires with a set of jumper cables. Use a multimeter to figure out ground, markers, and stop lamps. I did it during gone Moab while everyone was wasted and spray painting vehicles and someones head. Even if I did it during the day in a comfy environment it would have taken me forever without a multimeter. I remember splicing two of the factory wires together and connecting them to one of the led's.

[Ryan Gee]

The trailer converter changes things down to a two filament operation per side. So normal trailer lights work.

[Bobby B.]

Thanks for the input everyone.

Now I just have to find some spare time to do it.

[Bobby B.]

Been meaning to do this for a while, wanted to post up a quick update.

White wire is ground. Things worked better after that. Found a cheap easy solution for the turn signals.

Used a pair of inexpensive motorcycle running lights for $19. Good thing about these is that they're cheap, use regular bulbs so they flash normally and can be seen from the side as well as the back. You can also get a three wire version that will fit the bill for both a turn signal and running light. I just mounted them on the side of the temporary bumper we made that will stay in place until we begin building the bed.

http://img529.imageshack.us/img529/3424/light2le8.jpg (http://imageshack.us)

http://img110.imageshack.us/img110/3016/light1fo0.jpg (http://imageshack.us)

[tbecktold]

Very cool! Can we see a pic of the whole truck?

[Bobby B.]

This is the only one I have showing the temp fenders we made to keep it street legal for the time being.

Heading off into Sandstone Canyon down in Anza Borrego last month...

http://img176.imageshack.us/img176/5121/imgp7238vr9.jpg (http://imageshack.us)