check your yardstick
I checked the charging voltage of the alternator, and it measured 18 volts while running. Worried about an exploding battery and dreadful electrical malfunctions, i took it to a alternator rebuild and they tested it there as i watched.
Their tests had it charging at 14.4 volts. Their voltage checker was a damn sight better than mine. I then applied my $20 voltage meter, and it read 18. BOING! They suggested my voltometer needed a new battery or was junked.
I almost bought a new volatge regulator etc. based on the voltage reading of that cruddy meter.
lesson: get a second opinion, in case your test equipment needs testing.