CBR 250R Headlight - Fitting a Switch.

[menzies233]

I have a CBR250R that powers up the headlight as soon as the ignition is switched on.(Engine not started) I fitted 55/65W Nightbreaker unlimited halogens to get better lighting but find that they are quite heavy on the small battery.

I fitted 5W Ultra bright white LED's in place of the 5W filament bulbs in the running lights to improve my visibility, but now wanted to fit a switch to the headlight so I can turn it off during the day if the conditions are good so my battery can charge better on shorter runs.

I notice that almost all of the switching on this bike is done via the negative/ground side of the bike.

What are the main drawbacks if I put my switch on the live side? (It will be dead once the key is turned off anyway)

Reason being, if I switch on the negative side it will kill the hi and lo beam altogether unless the toggle is on. If I put the switch on the low beam live wire (I think it is the white one) then even with the light on/off toggle in the off position I will still have the high beam and the Hi Beam flash switch which I would like to keep available.

Personally I can't see anything wrong with using the switch on the live side, anyone suggest any problems, or has anyone done this mod to their bikes?

Cheers.

I cannot understand why Honda would set the lights to come on as soon as the ignition is switched on, the little MSX doesn't fire the headlight up until the engine starts, a much better way of doing things IMO.

Edited January 16, 2016 by menzies233

[papa al]

you are correct sir.

[canthai55]

A better - and safer - way to go is to use a relay. Then the switch does not need to be of a high amp rating, as all it is doing is turning the relay - which is in effect a remote switch - on and off. Hot wire to Relay, small wires to and from switch, hot wire from relay to headlight. If you want to get fancy, wire the relay switch to an oil pressure switch. Then when the bike starts and oil pressure rises, the headlight will come one. The reverse when you stop the engine.

[menzies233]

A better - and safer - way to go is to use a relay. Then the switch does not need to be of a high amp rating, as all it is doing is turning the relay - which is in effect a remote switch - on and off. Hot wire to Relay, small wires to and from switch, hot wire from relay to headlight. If you want to get fancy, wire the relay switch to an oil pressure switch. Then when the bike starts and oil pressure rises, the headlight will come one. The reverse when you stop the engine.

That is a really nice idea and would be perfect, however there is no oil pressure switch on the CBR. I will certainly fit the relay as I already have a spare.

Thanks for the ideas.

[menzies233]

Definitely putting the switch in on the low beam, you can hardly work on the bike for 5 minutes with the ignition on before the battery is taking a big hit, never mind the higher wattage low beam bulb, it is only a 20 watts more than standard and the number plate light and front DRL have been replaced with LED's.

Just trying to set the rear brake pedal light switch tonight almost had my battery down to a low level, seriously, not even 3 minutes.

55W low beam, 5 W rear, 2 x 5W DRL, a few presses on the 35W brake light, say maybe 5W for the dash etc. a total of maybe 110-120W? It adds up quickly, and the piddling little Yuasa Battery is way down. Gonna fit that switch ASAP.

[Generalchaos]

I bought an H4 Extension from E -Bay for about 100 Baht, (it is only about 6 inches long it is Male / Female). You can plug one end into the stock harness, then cut the low beam cable on the extension and wire that to a switch (20mm LED Illuminated fitted into the black plastic surround near the speedo).

You can then turn off the low beam when starting the bike for maximum power and once the bike is running switch the light back on. If you use decent cable there is no need for a relay as it is only about 4A and the extension socket has heavier cable than Honda fits.

The main reason I did this was to preserve the original wiring harness. If you want to revert back simply unplug the extension cable.

The one I got was from "aftermymusic" (E-Bay - 165 Baht - Free shipping)

Edited May 25, 2016 by Generalchaos