LED tail light question

I am looking to get a brake light and keep it all under the stock lense for that clean look, likely going to have to be an LED, can an LED work off AC power that the stock bike produces?

The quick answer is no to AC power. The best thing you can do is buy a rectifier unit, whether it be a motorcycle one or a 12V-15V 1Amp(12-15 watt) device and a capacitor(30V 2200microfarad electrolytic) from a model/ electronics shop. You don't need a regulator unit because the LED circuit has built in resistors to limit the current (milliamps) that they use.Wire the capacitor to the rectifier and insert the whole circuit into the rear lighting wire harness under the seat.You should now have a nice DC supply to the lights. Do not be tempted to try the filament bulb on this circuit unless your rectifier is rated at 30watts and you want a meltdown(p.s. the fumes are toxic).

Now you can decide to either search for a ready made unit to fit or make your own like I did. If you have a basic knowledge of electronics, its easy to do, or ask any electronics shop to help. I used 20 high brightness red LED's( 5 for the tail, 15 for the brake) arranged in a triangle, and 5 Super bright white for the plate illumination(cool blue white light!). All of these were mounted on prototyping circuit board and linked to 1/4 watt resistors. The project cost less than £20 (~$17) and took about 5 hours to make and fit. Have a go, I enjoyed it! The taillight now uses less than 1 watt compared to 26 watts (brake and tail iluminated) and my headlight does not dim at all!!

You can buy a 20A+ "bridge rectifier" for a few bucks. You already have a regulator, the stock bike runs the headlight/taillight through the regulator. The rectifier changes AC to DC, but you will need the capacitor to smooth out the DC. This is the cheapest way to go.

However, for a bit more you can go with a regular 150W dual sport regulator/rectifier and capacitor. Not only is it heavier duty than the stock regulator, but it integrates the regulator/rectifier in a single unit. This will make it easier to build your own dual sport kit in the future.


I have an extra spare rectifier I think, it is one of those square jobbers with a hole through the middle, two leads and filled with black epoxy. The other option I considered is those small LED marker lights that appear to use the same socket as our stock running light, the package on the back actually states it is OK to use AC through them. Decisions.

It sounds like it would be way too complicated to get an LED light. Why not just order the brake light kit from Baja designs for 45 bucks. It comes with a hydrolic switch, all the wiring, a new dual-filiment bulb & socket. It's easy to install.

Just for ideas, on mine I bought the baja designs brake light kit. I also have a baja designs re-wound stator. As a second brake light, I bought a fender drop down & rear LED light for a 04 DRZ-400. It was a bit more $$ than aftermarket parts, but it looks ok. Anyways, I hooked the LED light up so that it only comes on when I hit the brakes.

remember, LED lights will not work if polarity is crossed.

So the baja designs one fits under the stocklense? I also already had two hydraulic switches laying around that fit the rear master cylinder.

if you already have the switches, you might be able to just order the socket & bulb. YES, it does fit under the stock lens. read the install instructions and make sure the buld isn't too close to the lens, it will melt.

Let me see if I can find a part number. I'm bored right now anyways.

Damn, they doubled the price from when I bought it. Sorry man, the kit is 85 bucks. the part number for the kit is 14-9015. If you have a switch already, I would call them (800) 422-5292 and ask if you can order just the socket & bulb. tell them it got broken or something. You'll have to run your own wiring, but that's not too bad.

Too late :thumbsup:, I have already wrired in two LEDS for a brake/tail light.

cool. glad it worked.

Too late :thumbsup:, I have already wrired in two LEDS for a brake/tail light.

Let's see a pic. I was lurking over in the DRZ forum (thinking of buying one for the boy) and saw this: LED tail light

I will try and get a pic tommorow, the way I hacked up the two 194 sockets to fit them under the lense is mildly embarassing though. I think I am going to make an LED board and affix to the lense itself now that I have wiring for a brake/running light circuit.

So which rectifier did you go with? And where did you get your LED's? Im about to make a 650r street legal and I really dont want to use a Baja Designs kit. I want to use the stock tailight assembly and use a XR's only plate holder.

My bikes electrical is still AC power, no rectifier.

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