I got a 2011 Sportster 1200 back in February and it's been pretty much problem free since then.

I noticed over the past month or so that it was consistently having slow starts, even after sitting on the trickle charger all night.

Earlier this week I wrapped up a day at work, hopped on the bike, and as soon as I hit the ignition the bike went dead on me.

Eventually I went down and picked up a replacement battery (Duracell Ultra, CYL10002) and headed back to the garage to swap it out. While swapping I noticed there were two pigtails on the positive terminal. A long one that hangs below the bike that I typically use and a short one up inside the battery case. The short one also had a ground wire to the frame.

The short one was also fried. The plastic was melted and one of the wires looked like it had heated up to the point it snapped. That looked bad, so I removed the cable completely, and installed the new battery with the three other wires that were connected to the positive terminal (one being the lower pigtail, one going off to the starter, and I'm not exactly sure what the third one was traveling to).

I started the bike up and it started perfectly, faster than it had started in months. Thinking my troubles were over I cut the engine, drove my car home, and came back the next day to get my bike. I noticed it hesistated when I fired it up, which seemed odd for a brand new battery.

On the way home I had to make a stop at the hardware store, and when leaving I thought it wasn't going to start. It clicked, paused, and then turned over. This was after a 40 minutes ride.

So this got me thinking as to what could be wrong. First off, I'm wondering if that extra pigtail I removed was providing ground to the positive terminal. I know the negative terminal typically has ground, but is it common on bikes to have a positive ground as well? If that ground was removed, as I had done due to the burnt wire, could that be causing an issue?

If it's not the ground, then I start thinking the starter might be out or the charging system is not doing it's part. I have an voltage meter around here somewhere and I should probably check the bikes voltage on & off. But I figured I'd get this posted first and see if the ground cable I removed from the positive terminal is some kind of glaring issue.

Thanks

 

Check the regulator as well.

 

Check your battery cables, especially where the negative connects to the engine case.

Should not be a "positive" ground wire. Maybe the PO had some accessory wired in that needed the other pigtail. One of them is for a battery tender hookup that I believe came factory installed after a certain date, I think.

John

 

I hooked my charger up and noticed the lights didn't shift to indicate it was charging.

So I pulled the cables and saw a fuse on the pigtail. Checking it, it was a blown 7.5.

So tomorrow I'll replace the fuse on that. But that should only affect the pigtail right? Not the charging system during riding... right?

Found my multimeter was crapped out, so I'll be picking up another one of those tomorrow as well.