A glowing amp light is normal, and you can learn a lot with an multi meter. But there are many problems which cannot be measured easily with the meter.

My fuse block also looked ok, but after rebuilding it, stuff in my car all of a sudden worked better. If you have the tools I suggest you do it as it is a cheap effective upgrade. It was quite easy, but you will need a soldering iron big enough for the task. You will also want to get some of that anticorosive electrical grease/paste to protect your handy-work, once you have it you will start using it all over the place. It took me a little over an hour to take it apart and solder it back. My stereo worked way better, and many intermitent problems went away. But you could gain all of this by simply replacing the fuse block.

Another very easy and very common cause of charging problems is the battery to ground connection. I just had this issue come up on my car. My car all of a sudden wouldn't start. I finally tracked it down to a corroded battery grounding point. Took it apart, and sanded it down to bare metal and it worked great, about a five minute fix (once I figured it out).