When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Had an almost no start at a rest area. Check engine light came on. Codes said low volt ECM and high volt ABS. Cleared codes. Did not come back on on cold start next day.
Volts on battery 12.7 cold. Turned ignition on for a few minutes and volts dropped to low 12s. Started bike and volts dropped to 7.9 lowest reading on startup. After startup, volts consistent at around 14.5 even at high revs.
Time for new battery? Think ruled out regulator? Think battery failing load side? Battery is stock from 21 Roadking. Connections checked and seem tight and clean
First cold spell, or hot spell, can show weakened battery. A battery check can be done. I also consider the age of the battery. If over 5 years, I just replace it if no other issues arise.
To check, I charge my battery outside of the bike. Let it rest for a couple hours. Then check at rest voltage. I will do a load test and monitor voltage. Since you already saw 7.9 volts on startup, I'd bet you have a bad cell.
You just load tested the battery when the voltage dropped to 7.9 volts while cranking and it failed miserably. I'd do an actual load test to confirm but you need a new battery.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.