At this point the ‘Enginator’ was working, but there was still one major obstacle to be fixed. The carbon pile voltage regulator was not working. It was ‘stuck on full’ charging the batteries at 168 Amps at 44 Volts (for a 32V system). Running the Enginator would ruin the 4 8V golf car batteries in very short order.
Safety Car Heating & Lighting Company Carbon Pile Regulator (annotated by John Grube)
A month earlier when John Grube was out helping us he had noticed that the Safety Car Regulator was frozen up. Its job is to regulate the voltage and current output of the generator by means of a voltage and current coil that through a series of levers compress a set of carbon discs (aka carbon pile) which then change resistance and regulate the current to the generator field which, of course, controls generator output. John did a bit of research and found that Eric Hopp, a fellow rail had published the voltage regulator manuals on his site (http://erixrailcar.com/techpubs). This gave us a pretty good idea of the operation of the voltage regulator, including procedures for adjustment. It is always nice to have manuals for this old equipment! Coincidently, one of our volunteers, Larry Kuehn, noted that the Milwaukee Public Museum had a new exhibit from Allen-Bradley featuring carbon pile regulators.
John reviewed the manuals and suggested we take apart the linkages and make sure they operate freely. 
- Making sure the voltage regulator linkages at the current and voltage coils are moving freely.
Doing so revealed that one of the dashpots was frozen. The dashpots act as pneumatic dampers to prevent unstable operation. They contain a graphite piston in a brass cylinder with an adjustable screw to adjust how much air is released when the piston is moved up or down.
I was able to use some #400 sandpaper to sand a ridge off the end of one of the cylinders that was causing the piston to bind. It took a couple of attempts to get the piston to move completely freely in the cylinder.
Dashpot showing graphite piston and brass cylinder.
After reassembling the linkages (lightly lubricating them) and dashpots the regulator moved freely! Now it was time to run the generator and see if it was going to work. We started the Enginator and the result is 35.4V and 39A output. Perfect for charging the batteries! This will not overcharge the batteries. Special thanks go to John Grube and Eric Hopp for their collective help in getting the old carbon pile regulator working.
35.4V at 39A output. Perfect!!!