View Full Version : Sportster battery DRAIN

04-17-2014, 4:47 PM
Hey guys,

I'm having an issue sourcing the problem for my Sportster battery drain
Bike: 2002 1200

Problem: Battery slowly drains over the course of 2 days. On second day not enough to power the starter. click click click

I already bought a new starter relay,
New battery,
cleaned and tightened terminals,
Gone through the bike for a ground and couldnt find one

Anyone go through this?
Any idea of what to check next?


04-17-2014, 4:52 PM
its pretty easy to find parasitic drain. check out this vid and tailor its advice to your bike. the guys a little wordy but skip ahead a bit and it should give you what you need.
<iframe width="560" height="315" src="//www.youtube.com/embed/KF1gijj03_0" frameborder="0" allowfullscreen></iframe>

04-18-2014, 5:42 AM
Open your FSM and perform the regulator bleed test.

04-19-2014, 2:54 PM
If you have a volt meter (digital preferred), there are several things you can and should check. Static battery charge, running battery charge, short in the stator, running stator voltage, short at voltage regulator. There should be an electrical diagnostic flow chart in the FSM that will guide you step by step in isolating a problem source.