Find the voltage regulator. Set you meter to AC. Start your engine and run at full throttle. Across the two mark AC terminals of the voltage regulator you should 28 VAC or more. Now switch you meter to DC. Ground the negative (black lead) to the frame. With the positive (red lead) check the DC terminal for 13-14.6 VDC. If the AC is not present you have a bad stator. If the AC is present and DC voltage is the same as the battery then the regulator is bad.
IF both are good then you have drain that is out pacing the charging system. Note: A partially short electric PTO can still operate but draw excessive current out pacing the charging system. In this the case, check the electric PTO coil resistance if below 1.7 ohms it is partially shorted and PTO clutch replacement is needed.
