Hydraulic Brake Light

I'm considering doing my own dual sport kit and have a question about the brake light.

I will install a hydraulic brake light on my WR.

I plan to leave the headlight and "Taillight" on the AC side as is stock.... BUT!....

... Can I run DC power to operate the brake light only?

I mean, leave the taillight on AC so it does not drain the battery and only run the brake from the battery?

Is that possible? That would be better if so.

Hope that's not a stupid question.

I put the brake switch on my 2000 WR400. I don't see any problem with running it off the battery. When the brake pedal is not depressed it won't drain it.

The problem you will have is that the tailight and the brakelight share a common ground in the socket. The bike is set up with the frame as the AC ground (one leg of the stator is grounded to the engine case). If you put a rectifier and battery on the bike you will have to float either the AC or the DC ground as they cannot be tied together. It is much easier to float the DC ground because to float the AC ground involves rewiring the stator assembly. Bottom line is that both the taillight and the brakelight should be on the same ground, be it AC or DC. I have my '01 WR426 setup with both lights on DC with a 1.2 ah battery. No problems yet with draining the battery. The stock taillight is only 5 watts.

I'm considering doing my own dual sport kit and have a question about the brake light.

I will install a hydraulic brake light on my WR.

I plan to leave the headlight and "Taillight" on the AC side as is stock.... BUT!....

... Can I run DC power to operate the brake light only?

I mean, leave the taillight on AC so it does not drain the battery and only run the brake from the battery?

Is that possible? That would be better if so.

Hope that's not a stupid question.

That is exactly what I did with my 03...ran a short wire from the battery + to a fuseholder.Fuseholder to switch, other wire from switch to the yellow(IIRC) wire. Blew the 1A fuse I tried 1st, the 3A is working fine... :)

I'm considering doing my own dual sport kit and have a question about the brake light.

I will install a hydraulic brake light on my WR.

I plan to leave the headlight and "Taillight" on the AC side as is stock.... BUT!....

... Can I run DC power to operate the brake light only?

I mean, leave the taillight on AC so it does not drain the battery and only run the brake from the battery?

Is that possible? That would be better if so.

Hope that's not a stupid question.

That is exactly what I did with my 03...ran a short wire from the battery + to a fuseholder.Fuseholder to switch, other wire from switch to the yellow(IIRC) wire. Blew the 1A fuse I tried 1st, the 3A is working fine... :)

Run a dual-intensity 1157 LED cluster bulb available at ANY autoparts store and wire it up at stated above.

You can then forget about having to float any grounds...

Oh yeah, it works on AC too. :D

My mistake. I was thinking he had a 400/426. On those bikes I think if you add a rectifier/regulator the AC will no longer be regulated and you will fry light bulbs. On the 450 it is designed to regulate both the AC and the DC circuits so it should work.

Yes, it works fine that way! I've been running mine that way since last May. I did change the 1157 bulb out to an LED one I got at Autozone. :)

ditto for me. I went really cheap and ran a piece of plastic tubing down to the brake pedal. inside the tubing I ran a piece of safety wire. I connected one end of the wire to the brake pedal and the other end to a mechanical brake switch mounted under the seat. It is cheap but I did not want to screw with the hydraulic brakes.

The hydraulic switch can be had for under $20 so it's not that expensive. You do have to bleed your brake line after doing it. I have a vacume bleeder so it's not that big a deal, if you don't have a bleeder it may be a little more difficult. The bleeder is a good tool to have down the road anyway and I think mine was under $40, had it for a few years now and can't remember what I paid for it.

Run a dual-intensity 1157 LED cluster bulb available at ANY autoparts store and wire it up at stated above.

You can then forget about having to float any grounds...

Oh yeah, it works on AC too. :)

I was looking at those today at Autozone.

Are you using the red LED one and how bright is it? I was looking for the white LED, but they didn't have it. I don't want to spend the $20 on the red one if it's not bright enough when you put it in the red tail light lens. :D

I had tried a red 5 LED 1157 bulb and it wasn't bright enough. The Max white 13 LED I got from Midnight Moose is good and bright. :)

LED bulbs, except for the #194 marker bulbs, shed light in a relatively narrow angle. They are much brighter from the top of the bulb than on the sides, so they work better in the stock WR tail light than in the 'side-mounted-bulb' Baja Designs (UFO) tail light.

Run a dual-intensity 1157 LED cluster bulb available at ANY autoparts store and wire it up at stated above.

You can then forget about having to float any grounds...

Oh yeah, it works on AC too. :D

I was looking at those today at Autozone.

Are you using the red LED one and how bright is it? I was looking for the white LED, but they didn't have it. I don't want to spend the $20 on the red one if it's not bright enough when you put it in the red tail light lens. :)

Yes, teh red ones aren't bright enough. The white one certainly are. :D

When you run the LED bulb is the intensity lower than it is on 12 volts DC? I know it will work but it only is 'ON' for half of the AC cycle so I would think the output might be diminished a bit. Anyone done a comparison? Then again if the output is adequate it really doesn't matter.

I'm not sure. All I know is that mine is plenty bright!

When you run the LED bulb is the intensity lower than it is on 12 volts DC? I know it will work but it only is 'ON' for half of the AC cycle so I would think the output might be diminished a bit. Anyone done a comparison? Then again if the output is adequate it really doesn't matter.

The AC frequency (related to RPM) is high so your eyes shouldn't pick up any flicker.

I wouldn't expect that you would see flicker but the rms voltage to the bulb will be lower than 12 volts. I don't think it matters as it seems that it's bright enough. Just a curiousity :)

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