This is the way I see it:
I was told by some of the guys to always switch negative as a standard. You could switch positive on this board but I like to follow standars and now any time there is a switch leg I switch negatieve no matter what it is.
What I didnt show in the diagram is hooking up more than one solenoid or the fact that I use color-coding for the solenoids coming off the board. So in this diagram the wire from the RCE200 to the Solenoid might be yellow (haymaker), orange or purple (sterns), white (port bow sidemount) or blue (starboard bow sidemount). I dont have any 3 guns ships so now third color at this time for the trip sterns.
I like the color coding as it helps ensure that I connect the wires in the right order. So for the sterns I prefer to run two differnt colored wires connected directly to the RCE200 rather than splicing the wire down the line which introduces a break in the line and an additional failure point, and its easier to do it this way when color coding. I also do not solder the wires 'into' the holes but flat across the connector as its easier to make a change if I am changing out the board. A pondside soldering iron is hot enough to unsolder the wire and I have had some many problems with mini-deans that I am trying to get by without them where possible.
Don't be confused by the '+++' on the RCE200 board. That is not for positive necessarily but rather for the load.
I hope this helps you out.
Johnny