14.13 volts is perfect, ... Right between 13.75 and 14.75 volts, but that's just the first part of the test. Next you'll need a professional load tester to test the output current. If your generator has a defective diode, you will only be able to get exactly one third of the rated current, and "ripple" voltage will be very high. 30 amps from the common 90 amp generator isn't enough to run the entire electrical system under all conditions. That can be enough to turn on the warning light.
Tuesday, March 11th, 2014 AT 2:52 PM