It had completely slipped my mind when my alternator fuse blew, but I own a
cheap(under $10) Battery & Alternator Voltage Checker. I just ran across it and it gives
me the results I was looking for. You check the battery with the engine not running and
the readings will be: (1) poor/5.0v; (2) fair/12.0 or good/12.5. The engine needs to idle at
2000rpm to test the alternator and the readings are: (1) low/13.0; normal/13.5 or
strong/14.0. Recommend one for every tool box.
