Which wire for a brake light?

Wallydog · Apr 28, 2004

I am doing a minimal dual sport on my KDX 220 and thought I could just split the hot wire that runs to the taillight to power the brake light. Doesn't work. When I put the brake on the brake light barely lights and everything else goes dim. There must be another hot wire I can plug the brake hot wire into. Anybody know which one? Thanks

Dewster · Apr 28, 2004

I installed a dual sport kit on my KLX and did the same thing but it works fine. You may need to install a battery pack. Your stator may not have enough juice to power it all. I was lucky, when I installed my kit all works fine... even the horn. My headlight/taillight does dim a bit when on the brakes and the turn signal is on.

rethnal · Apr 28, 2004

A capacitor works good for sudden hits... but diminishes fast. Get's you through the dimming.

Wallydog · Apr 28, 2004

Capacitor ?

Not sure about a capacitor but assume it goes inline on the brake hot wire? What kind and where do I get it? I wired this same way on my old XR with not a problem. I can't believe there isn't enough power somewhere that I can rob for the brake light with out overloading the whole system. I do not want to rewind the stator or buy a bigger one. That sounds expensive. All I need is a brake light and I can get inspected. I plan on using a squeeze air horn. Beep beep.

rethnal · Apr 28, 2004

Visit any car stereo shop or even Radio Shack and ask to see their capacitors, I would say a .250 farad cap should do it just fine. I would put it before the regulator. Essentially they are a short term storage battery and should be treated like a battery.

speedracer238 · Apr 28, 2004

Wallydog....Where did you buy your brake light kit from? I planned on doing the same thing.

carney · Apr 28, 2004

The other thing you could look into is an LED tail/brake light. They use almost no power and last forever. I saw them at Autozone the other day.

rethnal · Apr 28, 2004

Hey carney! The only thing you have to look out for on LED's is that they require EXACTLY what they say.... any less and they won't light, unlike a conventional bulb but if your under the total output then you should be fine!

carney · Apr 28, 2004

Hey renthal, was just reading some of your other posts and laughing about your creativity in the mention of the "unspeakable" :laugh: That's a good point about the LED's, I haven't really looked in to them fully.

Wallydog · Apr 28, 2004

Thanks but......

What i am using for a tail light brake light is a basic two prong grounded replacement socket and the cheap 1157 double element bulb that fits it. All cost less than $5 at autozone. This socket fit right inside of the stock light with a little extra wire wrapped around it so it snuggly fit in the rubber stock socket holder. All in all a nice sano fit using the stock light if I can get it to work with rethnals capacitor. I will be buying one tomorrow. The other concept is a resistor to drop the amount of juice used for the taillight so when the brake goes on there is enough juice left to power the brake light. Would this work?

rethnal · Apr 28, 2004

Or you could make the tailight drop out of the circuit when the switch is hit and that would save you 5 watts or so! Use a dual sided relay.
There are a few other things that can affect performance, wire gauge and type, resistance, length, ground etc. I am assuming you are using a hydraulic switch and normally they do not present any problems.

jamin326 · Apr 29, 2004

i wouldn't put a resistor in there it's just going to waste power and not going to help you at all. a light bulb is like a resistor in that it dissipates power, it has a voltage drop across it and a current draw, a resistor will do the same thing cause a voltage drop across it and draw current, not what you want to do.

jamin326 · Apr 29, 2004

hey renthal how would you hook up that relay i'm curious

rethnal · Apr 29, 2004

From the regulator the master power lead goes to the relay on side A and powers the brake switch (Y). On side B, you have a relay lead that does the on/off switching and this lead goes to the brake light switch. The other two leads on side B goes to the brake light and the tailight and this is what the brake light switch controls...the switching between the two lights. One constant until switched (tailight) One switched (brake light) Get it? I hope that was clear..... :)

Wallydog · Apr 29, 2004

Tried it but did not work...

Well I went to Radio shack and bought a couple of different capacitors, a 225 and a 450 to try along with a 5 watt resistor. Nothing worked to help. All goes dim when the brake goes on. Yes I am using a hydraulic brake switch. Even tried a 6 volt bulb but still no good. I am confused at your relay describtion and Radio Shack had no such thing. I did see a RC car battery pack that puts out 9.5 volts and that should power a brake light for a long time. Thinking of setting that up on its own circuit to power the brake switch and light. Presto. Chango. Will I have brake lights then?

rethnal · Apr 29, 2004

Are those micro-farad capacitors? If so... I doubt they could hold enough juice to light it. Geesh... we need to get you going here! Now... you are going to get some dimming no matter what you do if you go over 38 watts. Headlight 20 watts, tailight 5 watts and brake light 20 watts for a total of 45 watts. Your bike may be rated at 45 but that really doesn't matter, it will dim. I would replace the lighting coil with a 75 watt coil to end the suffering here! :) They are only $85 and I guarantee you will be smiling! http://www.frpoffroad.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=FRP&Category_Code=MOOSE2
Be patient... his site is DOG@SS slow!

Actually Wallydog... check your ground wires before going any further... One of the first things you learn in electronics! You cannot have a good circuit without a damn good ground! :clue:

Wallydog · Apr 29, 2004

Micro-farads

Yes the 225 and 450 were micro units. They did not have a 250 farad. Yes I need more watts. I don't want a lighting coil because that involves a flywheel pull which involves buying a FW puller etc. I just thought this would be a simple deal. Trying to keep the $ down. I am still thinking of the RC car battery pack. $29.95 for the charger and pack together at the Shack. Should be a simple circuit to hook up. I could even wire a horn into it. I have enough spare parts from all the other attempts to put that together. Probably blow the bulb with that power source. Tempted to try it though. I guess its time for me to go back to Electronics 101. Thanks for the help.

rethnal · Apr 29, 2004

Actually Wallydog... check your ground wires before going any further... One of the first things you learn in electronics! You cannot have a good circuit without a damn good ground!

Wallydog · Apr 29, 2004

Ground

That much I know. The factory ground is what I am using and the tail light using that ground burns bright as can be. I think I need a tail light /brakelight that draws less wattage.

rethnal · Apr 29, 2004

You cound try the LED ones you get at AutoZone.... may be worth a look see.... Those RC power packs sound like a cool idea... 14V?

jamin326 · Apr 29, 2004

renthal that wasn't really clear, i'm guessing your talking about using a double pole relay, and using the brake switch to go across the coil and switch the relay. you would then have the taillight hooked up to the normally closed side on one pole and have the brake light hooked up to the normally open on the other pole, right?

rethnal · Apr 29, 2004

You got it! Still only save about 5 watts... :ugg:

jamin326 · Apr 29, 2004

with the 1157 light bulb you are definetly drawing too much power the bulb is split 21w/5w, the kdx manual says the taillight bulb is a 10w and the headlight bulb is a 30w, if you replace the headlight bulb with a 20w then find a dual filament light bulb with a 10w/10w split and you'll be all set, i think i put a 20w bulb in my headlight becuase the kawasaki stock replacement was like 20 something bucks and for like 7 bucks i got a two pack of some 20w bulbs

kx200 · Apr 29, 2004

use a LED tail light can find them here
http://www.superbrightleds.com/led_prods.htm

rethnal · Apr 29, 2004

I have such a 20w headlight bulb lying around! :) I assumed that's what he was using.... that splains it!

From that site:

NOTES CONCERNING TAIL/SIGNAL/BRAKE LED BULBS:
For best results the LED color should be the same as the lens color

LED brake/tail lamps may not work with some thermal flasher units due to their extremely low current draw. These installations will require an electronic flasher unit available at your auto parts store.

LED bulbs are generally not as bright as standard incandescent bulbs, they have many advantages over filament bulbs (longer life, faster on/off times, lower power consumption, more vivid colors) but brightness is not one of them.

Some of our bulbs are available with 12 or 19 LEDS, obviously the 19 LED units are brighter.

Some of our bulbs are available with Narrow or Wide viewing angle. The Wide angle (approx. 100 degree beam) will light up more area but dimmer than the Narrow angle. The Narrow angle (approx. 15 degree) will illuminate a smaller area but brighter than the Wide angle.

Which wire for a brake light?

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