Originally Posted by rickfly
did you ever think your key switch has poor contacts? have seen them fail and cause odd things to happen. a decent battery should read at least 12.8 vdc nat rest with a charge, and a charging system at idle should be above 13 vdc with 13.4-13.8 at fast idle. grounds are very important, use some antiseize on the connections after scrubbing the crap and cleaning them, make sure the top of your battery is clean and not bleeding current from post to post. to clean it use a rag wetted with water and baking soda and then wipe it with clean water and a rag.
I think that's timeless advice concerning undiagnosed electrical problems.