I was thinking that might be the problem. Electronic boxes like a more even voltage than the old mechanical regulators generally give, although you can turn them up a bit. I have the blue box on mine at this time, but plan to switch to the electronic regulator in the near future just to be safe. It's only a matter of a later alternator and a wire. Main reason is the easy availability of replacement parts. That said, I have a couple summers on the blue "race" box, and have no problems, and have never seen over charging at least by my old amp gauge. My electronic system is made up of all pieces I had laying around, and it works great. Don't give up on it.