I have the same problem on my '58. I thought I had a short to ground somewhere(everytime I turned on the headlights there was a discharge on the amp gauge) and couldn't find one so I rewired the entire truck and replaced every electrical part on the truck except the ignition switch.
This was OK cause the wiring was pretty bad
BUT the problem didn't go away. Hmmm, maybe it's the generator. Just ran the test described in the shop manual and when I was suppose to get an amp reading while running the truck at medium speed, I got nothing. I'm going to try what Hot Rod Lincoln suggested tomorrow and I'll report back.


"What ARE you doing in the garage all the time"
58 Chevy Apache 3100 Stepside