You don't repair a bike by throwing new parts at it. Unless you feel VERY lucky.

You diagnose what is wrong, and DETERMINE what parts, if any are needed. For instance, a single loose connection might be causing your no-charge situation, rather than a bad "alternator".

Start by buying a voltmeter (or get one free at Harbor Freight with a $50 purchase of other tools) and measure your battery voltage, both engine off, and engine running.

A charged battery should show 12.6 or more. If the engine is runnign and alternator is working, at 2500 rpm you should show 13.4 volts or more measured AT the battery. If it's still 12.6, or down to 12.5 by now, your "generator's" not putting out.

So you check all the connections, battery ground to frame, alternator + to battery +, check the CONNECTORs to your , and check output DIRECTLY at the alternator connection.

If you have to take the cover off to get to the stator, then get someone more familiar with motorcycle electronics to show you how to test continuity/resistance on your stator windings.

To answer your question, electrical stuff, switches, motors, starters, alternators I always go with new or rebuilt, never used. Why put someone else's half-worn out part on YOUR bike unless you like replacing things twice. Or are too poor to afford new - and like I used to, hand rebuilt switches, etc.. Bikebandit.com has your part but it's TOO DAMN EXPENSIVE, I suggest eBay wher eyou can get a new set for under $99.

http://www.bikebandit.com/oem-parts/2005-honda-rebel-250-cmx250c/o/m151131#sch306855

 

http://imgur.com/gallery/buUZv

 

How it feels your first day working on wiring....

Consider this: As long as guy on wooden (insulating) pole doesn't touch TWO wires at the same time, or doesn't have his leg or body touching the copper grounding wire found on most utility poles, he's safe to touch ANY wire.

I've seen video of guys rewiring service entrances (masts) on old houses standing on fiberglass (insulating) ladders leaning against the house, completely free to touch/cut/splice 220V lines. (provided they don't simultaneously touch the grounded, metal mast itself, or two wires simultaneously)

In my mind I know it's safe, but... I just can't do it. I wear rubber gloves. I'm chicken. bok bok BOK!

 

There are plenty of components in your charging system. The alternator is definitely one of them but so is the wiring and the voltage regulator. If you just replace things one at a time it can get expensive. Either do the troubleshooting, if you are qualified to judge the results, or pay someone who knows how to do it. In the long run it will be cheaper than random replacements.