I'm sure your referring to the one in the back. It is coated with fluid film to protect it. That is the connection point for all the pump's and float switch's.
Ok, now think about this. Most boat's have the wiring all crimped and sealed for these and that's fine untill you have a problem and need to do some testing. Then you take a test light and stab the insulation to test for power. You have just screwed up the watertite integrity of the wiring.
So enter the terminal board into the system. Now I can prop the terminal's for power. I can also do a quicker componet swap too.
Here's the drawing.
