Hello, I have a 1987 DT200. For the first time yesturday while running at about 3500 rpms I noticed my volt meter was reading over 15 volts. I thought it was the guage, but my fish finder was reading 15.2 volts also. I've never seen a volt meter go over 14v in both cars and boats. Is my regulator gone? Can't this harm my batteries? Any ideas?