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dead battery - need help testing for short


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2007 250x, mostly stock, very low miles.

The bike has been perfect since I got it a month ago and I've put about 200 miles on it, previous owner 'about 200 miles' also.

I installed a Deltran pigtail on my battery in prep for a trip to ANF Trails. My plan was to charge my cell phone while riding throughout the day by hooking up a Deltran cig socket and my cell phone in a backpack.

Hooked it up on a Friday, tested it, all good, unhooked the cig socket and capped the battery pigtail with it's cover and coiled it up neatly in the air cleaner box (ala CCC mod). Bike started normally after this.

I decided not to use it the next day during the trail riding, as the battery in my phone didn't need it yet, figured I'd use it later in the day.

All is well, after about two hours of riding with several stops/shutting it off in there, the bike doesn't start via magic button. It didn't take me too long to realize that the battery was dead, so I simply kicked it the rest of the day. No big deal. Lights still work (kudos Honda for wiring it that way as opposed to directly off the battery), life is good.

So when I get home to charge the battery, it tests as "0.00" on the multimeter. I've never in my life seen a "0.00" on a battery. When they're low I see 11.xx but never 0! I took the battery out and tested it out of the bike, same thing (no real surprise there). Tested my son's bike right next to me, his was fine so I know the meter is working.

My Tender wouldn't even try to charge it. I have an old Sears charger that I hooked up to it set to trickle charge it at 2 amps. I come back in three hours, remove the clips and test the battery, still 0.00.

So I ordered and just last night received a new battery, this time the 450x battery with 6AH, but I'm afraid to put it in for fear of ruining a brand new battery.

And now finally my question.... how do I go about testing with the multimeter if there's a short somewhere in the bike wiring? I've completely removed the Deltran pigtail that I installed that started this whole mess and don't have any plans to put it back on. Although I've tested the pigtail and there are no shorts in that. And, I have the exact same pigtail on my street bike battery, for five years now, no problem.

The only other thing I did to the bike before this trip that might be relevant was I removed the taillight and was going to install the DRC taillight from CRFsonly until I got to the wiring part and decided that I didn't want to mess something up right before this trip, I'd do it later. (Wiring this light will be a new topic by itself). So I put everything back as stock and that worked fine. This was also the same night as the Deltran battery pigtail installation, the day before the trip.

I noticed about four hours into the trail riding the next day at ANF, well after the battery died, that the taillight was flickering. I don't know if that's how it normally operated when the battery is dead or if that is indicating a short in there somewhere possibly? It could have been doing that all day I don't know.

Anyway, I'm seeking advice on how to test for a short in the bike wiring (the 2-wire pigtail was easy) and what you might think is going on? Has anyone had this happen?

It completely ruined this newish battery that the previous owner installed a few months before I bought it.

The bike had been perfect until this, and no other electrical work was done. Obviously, I can kick it and it starts right away, but I'm hesitant to put a brand new battery in it till I can test it somehow.

I have the service manual coming tomorrow but to be totally honest, I'm not that great with wiring diagrams and where to test for shorts. Testing the two wire pigtail was fairly easy ;-)

Thanks!

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As for what you installed more then likey it was just Bad Timing Luck that all could very be the Stator that was all ready on it way to shorting it self out or Voltage Regulator Stop working.

To Check Voltage Regulator with battery voltage with bike not running. Start the bike (crank the rpm's up a little), voltage should be a 13 to 14.5 volts at battery if high then 15.0 you got problem. Check both voltage (running and not running) at battery terminals.

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I have the service manual coming tomorrow but to be totally honest, I'm not that great with wiring diagrams and where to test for shorts. Testing the two wire pigtail was fairly easy ;-)

Thanks!

Hook a meter set to resistance to the battery terminals with the bike off. It should read infinity. If you read anything less than infinity across the battery leads with the bike off, you have something draining the battery. The lower the reading, the worse the condition.

I suspect that the terminal readings will read OK. It is possible that you have an internal short in your battery. Even if you did discharge your battery to nothing due to a wiring error and even if the battery ended up damaged, your charger would be able to put a charge back on it - might not be able to supply much current, but you'd definitely be able to read something on the meter (provided the voltmeter itself is working and you don't have a blown fuse or something - better check that too).

JayC

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The only other thing I did to the bike before this trip that might be relevant was I removed the taillight and was going to install the DRC taillight from CRFsonly until I got to the wiring part and decided that I didn't want to mess something up right before this trip, I'd do it later. (Wiring this light will be a new topic by itself). So I put everything back as stock and that worked fine. This was also the same night as the Deltran battery pigtail installation, the day before the trip.

I noticed about four hours into the trail riding the next day at ANF, well after the battery died, that the taillight was flickering. I don't know if that's how it normally operated when the battery is dead or if that is indicating a short in there somewhere possibly? It could have been doing that all day I don't know.

I have no idea what it could be. The ONLY thing I did...

Where have I heard that before :smashpc:

ALWAYS check the last thing you did before a failure. On '06 and newer, the wire from the taillight to the ICM is hot and if it gets anywhere near a ground, it will blow a fuse.

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