Search the board with the keyword "voltage", you will find a number of things. Also, specifically check out this thread about my own troubles in this area.
http://www.337skymaster.com/messages...hlight=voltage
There is a good message from Bob Cook in there about what to check for, as well as a message from Gmas about alternator drive couplings. I would check connections etc at Bob describes first. For me, it was loose diodes.
I believe that Peter's board (
www.skymaster.org.uk) has some material on this as well.
Good luck Jim! (Always wanted to say that. Mission Impossible fan...)
Kevin