Hate to remind myself about a similar problem I had with my 69. I posted about this same problem with my car a few months ago. I had not disconnected the battery when I partially removed the dash to install my rebuilt clock. Same thing happened to me. Gen light drove me nuts ! I found a bad generator fuse in the under dash fusebox,after checking all engine electrical components :-( must have blown the fuse in my car when I loosened the dash ! Hope this helps !