My volt gauge has intermittently had two issues. One is waving back and forth between 10 and 15 volts and the other is staying in the red (16). I showed the service person who made an appointment and they wanted to charge me diagnostic since they said it was fine...of course it didn’t do it for them

 

You check connection at battery? The alternator/ regulator and battery are a loop. Regulator reads battery and knows how much at test rpm of 2000 to put out to supply power need and above the 12.7 volts of a battery. Normally around 14.7 or so depending in battery charge. If connections are bad, it does exactly what you are saying. And that battery connection is usually weak link due to either being loose or a little corrosion.

 

I will look into it. I didn’t do anything yet since it’s under warranty. The dealer doesn’t seem to want to fix it. I also have the migration problem and they said the vent fix is working even though it’s down to the add mark on the trans!

 

Had the same thing on my '05, battery cable was loose. Quick fix.

 

Thanks for the help guys!! I’ll check it out this weekend.

 

Welcome!

 

There is an issue with Voltage regulators going bad right now.

 

Years ago I had the same problem - loose connection at the gauge.

 

Yes. Some of the voltage regulators on the M8 have issues. I started having issues last week (battery not charging and staying at 12V) and am picking the bike up today after a replacement under warranty. I own a 2019 SG. After my issues I did some digging and see that it has been a fairly common issue (maybe a bad production run). Find a new dealer and ask them to check the charging system.

 

Every Harley I have owned has read 14.7