Andrew, that's almost exactly what I went through at the tail end of the summer, although our problems may be different. I, too had installed a solid state unit and tossed the old ones. I still had charging probs, so I picked up some used units, which turned out not to be good (rectifier at least), so I finally picked up new ones.
That said, there are obviously, there are more experienced electricians here; however, I can give you some starting points. The FAQ has a complete
Charging System Maintenance and Inspection Guide. I also relied on the factory shop manual, which isn't as detailed as the testing in the FAQ. The charging system section in the shop manual is only about 5 pages. If you've got a bike close to mine ('77 CB750), I'd be happy to scan it and email it to you.
One thing that I ran into that killed me was that my battery was new, too. I was mystified until I caught a post that explained that car battery chargers are not good for motorcycle batteries. My repeated charge/discharge cycles had killed it, although I didn't realize it because the battery would charge right up each time. I've learned that you need to test the battery with
both a volt meter and a hydrometer.
You'll need a multimeter for any testing. You may want to pick up a cheap one for about $20. Once you have one, you'll wonder how you got by without.
