Bill wins - there was indeed a wiring problem. i checked for continuity from the generator to the regulator, and it was (apparently) there. what a continuity check won't show you is if there is a short in the path. i read 0 ohms from the armature wire at the generator to the other end at the regulator, implying a complete circuit. I decided to read the resistance to ground of the armature wire and found that there was also 0 ohms from each end to ground. The wire was pinched under a bolt on the firewall shorting it out. when i repaired the short, the charging system returned to proper operation. thanks for all the help.
Tom
