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alternator charging???

Posted: Thu Jun 23, 2016 4:32 am
by vtxcandyred
Not good at liking things up. The battery discharges. I will have it tested but I want to test the alternator. I have a Radio shack cheapy meter. It appears as though I have under twelve volts at the battery with the bike running above idle and about twelve to almost thirteen volts key off. Engine running above idle I turn on different things to add load and the voltage drops little. Fully charged I can drive it about ten miles when I see the change in available power and it weakens from there. Charge the battery and it starts all over again. Battery is less than three years old. By the way the bike can sit for a VERY long time and it spins the motor right away with no hesitation.

Re: alternator charging???

Posted: Thu Jun 23, 2016 6:56 am
by Dusty Boots
Time for either servicing the alternator, or a new one. ;)


Re: alternator charging???

Posted: Thu Jun 23, 2016 8:40 am
At idle turn at about 800 you should see 12v's on a meter at the battery.

at 3,000 rpm's you should see 13.5 or so depending on what's turned on..that's what you "need" to keep the battery charged while running..actually 12.5 will keep it charged and running. but 13.5 is ideal. Over 14.5 also bad, can fry wet batteries; Ok for AGM batteries. that's usually a regular issue over charging.

less could be bad alternator, bad connections, bad regulator. bad battery/cell

Re: alternator charging???

Posted: Thu Jun 23, 2016 9:41 am
by keithg64
Could be that the brushes are worn out and need replacing. Not a hard job, a local alternator shop can tell you.

Re: alternator charging???

Posted: Thu Jun 23, 2016 12:44 pm
by MikeB
If it is a 1993, then it is most likely the brushes. I have not heard of winding failures on '95 and older alternators.

Remove the alternator. If you are so inclined, disassemble it and replace the brushes. If you are not the mechanical type, take it to an alternator shop and have them do it.

Reinstall it and test again. It will most likely be just fine.