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Discussion Starter #1
I'm making some do-it-yourself heated gear, and I'm looking for the wire that is on only when the engine is running.

Is there a wire that exists on our bike? I suppose I can take the fuel pump, but if there's another choice I'd probably prefer that.

I can drain the battery almost instantly, so I definitely do not want to run the gear without the engine on.

Of course I will use a relay so I don't add to the load of the wire.
 

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The Black/Red wire from the ignition key switch is where you'd tap into in order to have any accessories "switched".

Any powered accessories you install on the the bike should be made with their own individual on/off switches as well. For obvious reasons, you wouldn't want to have heated accessories like heated grips powered up all the time when ever the bike is running. Another reason that any/all powered accessories should be able to be switched off independently, is so that full battery power can be delivered to all the circuits associated with starting the engine.

The other consideration is the engines total alternator output, which is 340 watts. As I recall, the bikes electrical system requires about 130 - 140 watts when the engine is running, with all lights operating. In order to have a safe margin of electrical power from the alternator going back to maintain the battery charge, I'd say that any added accessories shouldn't exceed 150 watts of draw to the bikes electrical system.
 

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Use Battery Tender ends and just unplug it from under the rear seat when done. On long rides I stick mine out the back seat where I can unplug it on stops and not worry about the drain.

Much easier than splicing wires and taking a chance.

Heated gear also uses battery tender ends, so yeah it would be a simple job. Make sure the line has an in-line fuse. I use a 10a on mine.
 

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Discussion Starter #5
I'll grab the fuel pump wire without splicing. It will be also be switched and most of the time be below 80 watts. But a voltmeter and the fact that when you really need the gear:

A. you are likely to be on a longer trip
B. bike is 340 watts at 5k rpm, and more above that.
C. The faster you go, the more the windchill, but you have more power available.

I think my vest should be about 140W, but I plan on running half power, mainly.
 

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As someone who had his battery die from leaving his heated grips on I would recommend the tail light install. Or you can just get the gear you wear(much better at keeping you warm also IMHO) rather than some that stays on the bike and not have to worry about anything. Having to push start a 350lb bike isnt fun so I made a habit of not leaving anything on when i get off the bike also.
 

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The other option for heated grips is A'me chicane heated grips. Each grip has a microprocessor in it and they monitor the battery voltage. If they are left on, they will shut off if the voltage drops below a preset amount. Therefore, never leaving you with a drained battery.

http://www.cbr250.net/forum/cbr250-parts-accessories/6365-its-time-year-heated-grip-time.html
Sorry for the slight thread jack.
How do people like heated grips? When I had them the bottom of my hand was always hot when the top of my had was always freezing cold... Did I somehow manage to use them wrong?
 

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I'm making some do-it-yourself heated gear, and I'm looking for the wire that is on only when the engine is running.
Any wire that is 'hot' when the engine is running, will also have current when the engine is not running with the ignition key is ON and the kill switch is in the RUN position.
 

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Sorry for the slight thread jack.
How do people like heated grips? When I had them the bottom of my hand was always hot when the top of my had was always freezing cold... Did I somehow manage to use them wrong?
That's pretty much the nature of heated grips. They've been supplied as standard equipment on snowmobiles for decades, with a high/low heat setting as they will get very hot when full current is flowing to the heat elements. Most heated grip designs use a resistor for the low heat setting. On my snowmobile, I'll start out with them on the high setting, then after a few minutes turn them down to low... otherwise they would just get too hot under most conditions running on the high setting. The other aspect to having warm hands in cold temps, is wearing gloves that have more insulation on the top of the glove, and less on the palm side so that you still have good feel on the grips.
 
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