Alternator charging

[Jims99]

Just took a 550 mile ride and noticed (on the way home) the voltage was around 13.2 but dropped to 12.7 once in awhile, the voltage usually runs around 13.4-14.1 volts.  It was cold (54) but I don’t think that matters. I haven’t had any issues with alt. in the past, not sure what to check first. Could it be a bad ground, regulator or brushes. This is on the 2000 interstate with about 72k miles.
Thanks. Jim

[da prez]

   Also , my soap box. Clean all grounds. Remove , clean and I use silicone dia electric.  Corrosion causes resistance. Resistance causes heat .  Heat melts insulation.

                                                               da prez

[rug_burn]

Actually, that sounds totally normal.  In our (over)instrumented car, it does the same thing.   A good battery will usually read about 12.8 right off the charger, and settle down after half an hour or so to 12.6 volts, more or less.   
   When you rev it up, it'll come up to 13.5 to 14.2 or a little more.  Which it seems to be doing.
   If the battery voltage reads about 12.6 to 12.7 after sitting a while, it's good.  That's normal behavior.

[Jims99]

Actually, that sounds totally normal.  In our (over)instrumented car, it does the same thing.   A good battery will usually read about 12.8 right off the charger, and settle down after half an hour or so to 12.6 volts, more or less.   
   When you rev it up, it'll come up to 13.5 to 14.2 or a little more.  Which it seems to be doing.
   If the battery voltage reads about 12.6 to 12.7 after sitting a while, it's good.  That's normal behavior.

This was happening as I was cruising down the road. Rpm’s stayed up over 3k as voltage changed .
I’m leaning toward the grounds. Maybe because I want it to be easy. Just need the time to trace it down.

[Pluggy]

Grounds are a good starting point. Steady voltage around 14V at highway speed indicates the electrical system is working correctly.

[Rio Wil]

When above 1500-2000 rpm and the voltage drops off to 12.8 or so.....the brushes in the alternator are probably wearing out,,,,,or the infamous broken winding in the alt is rearing its ugly head.....

[gordonv]

My brushes on my 88' 100K GW, where no longer moving in the holder from dust build up. I would think every 5-10 years take the alt out and clean them and check how much of the brush is left.

I recall someone saying 35K and do it?

The best way is to add a volt meter to your bike and monitor it. When it starts showing lower than normal, time for inspection/maintenance.

[Pluggy]

Anyone blow the carbon dust out with compressed air, without taking the alternator out of the bike?  Using air and a shop vac seems easy enough.  Removing an alternator isn't so easy.

[da prez]

  Yes , compressed air with some thought. Start with a lower pressure a little distance away. Gradually get closer. Bump the engine over to change position of the armature. Watch for dust thru your safety glasses.
 All things in moderation.

                                                 da prez

[Pluggy]

  Yes , compressed air with some thought. Start with a lower pressure a little distance away. Gradually get closer. Bump the engine over to change position of the armature. Watch for dust thru your safety glasses.
 All things in moderation.

                                                 da prez

Thank you.  Certainly something to do outside.  I will try to keep the shop vac hose close to the alternator in an effort to capture as much dust as possible.

[MarkT]

My brushes on my 88' 100K GW, where no longer moving in the holder from dust build up. I would think every 5-10 years take the alt out and clean them and check how much of the brush is left.

I recall someone saying 35K and do it?

The best way is to add a volt meter to your bike and monitor it. When it starts showing lower than normal, time for inspection/maintenance.

+1.  You are beyond -72k - maybe average time to alternator fail which is closer to 50k.  Brushes usually.  I keep a spare alternator - especially on trips.  And brushes.  You can extend the life by lowering the load.  Change lights to all LED's.  Like Gordon says, if you don't have one already, get a digital voltmeter and watch it for changed behavior.  I did and that has saved me from a dead battery while riding, on road trips twice.

[Jims99]

I have a volt meter installed, that’s how I knew it was going up and down. Did a quick check on grounds and now going to try the compressed air. Already changed lights to LEDs. Road all weekend and voltage held between 13.6-14. The flux was on a 300 mile none stop ride.
How hard is it to change the brushes? Have over 70k miles on this one.
Thanks

[Chrisj CMA]

I have a volt meter installed, that’s how I knew it was going up and down. Did a quick check on grounds and now going to try the compressed air. Already changed lights to LEDs. Road all weekend and voltage held between 13.6-14. The flux was on a 300 mile none stop ride.
How hard is it to change the brushes? Have over 70k miles on this one.
Thanks

It’s not that bad to change the brushes. Harder the first time though.

[Jims99]

It’s not that bad to change the brushes. Harder the first time though.
[/quote]
I was just talking to Sixlow about that yesterday. Thanks.

[gordonv]

My post.

http://www.valkyrieforum.com/bbs/index.php/topic,107156.0.html

I didn't read it over again, but after few tries I've gotten pretty good at changing out the alt fairly quickly. A few tricks in doing it.