On my '68 Bee (383), I have something that I can't figure out. When the car is cold, the system doesn't charge. After several minutes, it charges ok and stays that way. I'm thinking that something warms up and makes a connection. I had gone through the whole system last year and put on a new alternator, and new voltage reg (one of the stock looking solid state jobs). I've also checked everything for good grounds and have cleaned all the bulkhead contacts. I still have the stock amp gauge but I also have a volt meter that is wired directly to the battery. It always starts out at 11.90 and goes to about 12.1 volts before it jumps up to 13.6-14.0 volts. Any ideas?
Take alt into auto parts store for testing. Also bring in battery for load testing. Buy another voltage regulator while your there if alt and battery check out. Try to replicate the temp of your alt by cooling it in the fridge and put it in a cooler on the way over to the parts store for testing.
Keep us posted
I have seen this before years ago. The problem with the one I encountered, was the alternator brushes sticking (due to corrosion and dried grease), once it warmed up, it released the brushes and charged. Quick and easy test to see if this is your problem: connect a voltmeter across the battery terminals to monitor charge and have someone start the car, tap the alternator case lightly and see if it charges.