The problem I was having was the battery would charge normally and bike would run fine most of the time but a couple of times it wouldn't start. The first time I got stuck out in the rain and sleet with a dead battery and had to call Betsy to give me a jump start I decided I needed to get my police bike back to it's old reliable self.
These are the basic steps for checking out the electrical system -
Verify battery voltage is about 12.8 volts DC with engine off.
Verify battery voltage increases to 13.5 volts DC to 14.8 volts DC with engine running. The voltage should increase as the RPM's of the engine increase. Turn on all electrical loads and verify voltage stays above about 13.5 VDC. It's about 13.5 VDC because the voltage of a fully charged battery is about 12.8 VDC, so the charging system needs to be slightly above that to keep the battery charged. If voltage is too low your battery won't stay charged and the bike will run off the battery - until the battery discharges to the point that it can't fire the plugs. If the voltage is too high you'll boil water off the battery and may burn out light bulbs.
Do a visual/meter-aided inspection of wiring looking for shorts or grounds.
Clean/tighten all connections.
Check voltage at the three stator wires is above 50 VAC.
Check voltage regulator diodes front to back ratio.I ordered a new voltage regulator made by Accel from Amazon. It took awhile to get to me but the price was good and it works fine. You'll need longer screws to mount this regulator since the form factor is slightly different than the OEM regulator from Kawasaki. This is a link to the regulator - Accel 201411 Chrome Motorcycle Voltage Regulator for Kawasaki. The Accel regulator is less than half the cost of the OEM Kawasaki part (68 vs. 152 dollars)
A few notes -
The regulator is sometimes called the RR, short for regulator rectifier since it Regulates - keeps the voltage between 13.5 and 14.8 VDC, and Rectifies - changes stator voltage AC to DC. Stator outputs 50 VAC to the RR which outputs 13.5ish VDC to the battery, lights, horn etc.
The electrical power on this motorcycle is provided by a rotor - a wheel with permanent magnets embedded in it, that rotates inside a stator - a stationary circular piece with coils of wire mounted to it that convert the rotating magnetic field to electricity.
The removal and replacement of the regulator is (like other things on motorcycles) made difficult by lack of access. The regulator is mounted under the battery tray and it took me about 3 hours to get the job done. I'm really happy to have bright lights and I'm looking forward to riding my winter bike to work today.