In process of adding a ballast system, going the reversible pump route. Trying to figure out how to wire this, the only hangup I haven't figured out is how to power each switch. I was planning on pulling power from the open battery spade, to a 14 ga power block, from the block to each switch, fused with a 20 amp inline fuse. The only thing I don't know is, can that little circuit board I am pulling power from handle this much current draw? Each pump is rated at 20A, not sure if I have all 3 pumps running, I don't know if that board can handle this? Has anyone ever measured how much current is being drawn when all 3 pumps are running? Thoughts?
Also, if anyone has a schematic of how to wire each switch, I think I have it, but just want to make sure I have the correct one. All of my parts from Wakemakers are coming Friday, I think it may come with a wiring diagram, not sure.

ballast wiring.jpg