Hello,
 I am new to this site so I don't know ow to do very much in here but I have an issue with my 770 gas that I thought I would post and see if someone knows the answer.  I ran the PTO for a couple hours the other day and after a while I noticed acid all over the battery. The voltmeter says that the generator was putting out almost 17 volts. If I drop the engie down to a low idle the voltage across the battery drops to about 13.8 or so which I would call normal. When I rev up the engine the voltage across the battery rises as well. I went and bought a new regulator from NAPA and I got the same thing. The generator and the regulator have been on the tractor for at least 20 years as I have had the tractor that long and have never changed either one. I don't normally run the tractor for very long at one time so it is possible that this condition has existed for some time. The wiring on the engine is original but the wiring behind the gauges is junk as are the gauges. I have just purchased new gauges but have not installed them yet. I did hook up the amp light according to a manual I picked up years ago at the local Oliver dealer and it works as expected. The light comes on when I turn on the key and goes off when I start the tractor.
   Does anyone have any idea what my issue is here?