I thought of that too since I had a problem and replaced the
Masterswitch. I do not have the split one. But is seemed the oscillation
was too slow. Mine you could see on the ammeter like it was waveing to
you. I also cleaned every ground I could get my hands on.


Regards, Ross
C-172F 180HP
KSWI


Paul kgyy wrote:
Us Cherokee types also have an overvoltage regulator to deal with.

One other simple cause may be the master switch. The portion that
connects alternator to battery carries a fair amount of current and the
contacts get pitted and corroded over time. A bad connection can
result in voltage fluctuations.