Wiring the Bauer

Jim suggested before I do anything that I understand the existing circuitry- I drew a very crude sketch and then put it into an e-CAD program.  Which was actually an adventure- simple diagram drawing is hard to find.  Everything is either digital circuitry (and most allow you to go right to a PCB) or not electrical in nature.  I ended up with TinyCAD.  I was happy with it see what you think?

I had a big white box at the top of the control box that I couldn't figure out- turns out it was a timer.  I guess I should have known when it said on it "15 minutes, 6 seconds"

Now, this is a typical electromechanical way to control the compressor.  Newer ones are computer controller, and I may go that route, because I want to learn to program an Arduino. 

But before I think of that, I need to figure what all these 4 bundles of wires do.  I'm guessing some of it is power.  Then there is an overpressure switch.  And an oil pressure switch.  On the panel there's an oil pressure override.  Maybe one is for the hour meter?  Time to start tracing wires.

(in progress)