Low Voltage Output on Big Inch Modified

[jdawg]

I have a 99 FLHTCUI bored & stroked to 120" by Marcum Racing:. In addition I replaced the factory stereo with a high end alpine during the rebuild. The problem I am having is the volts drop below 8 at idle. This occurs now even when the radio, accessory switch, running lights etc are turned off.

It seems the battery isnt charging, and that there is only about 10volts output even @ 3000 RPMs but I cant tell because of the additional cranking amps the big inch motor draws. Any thoughts?

Should a heavy duty or 3 phase 40amp chargins system be added with the big inch and stereo upgrade?

:42:

 

[glider]

8 Volts at idle is too low for any system to operate correctly.

Here's the proceedure to test the system out.

http://www.hdtimeline.com/electrical_and_lighting_systems/741-testing_the_charging_system.html

If starting isn't a problem the system you are running should do the job if it were operating right.