I have a similarly bizarre setup on my 32-3. One Rule 500 in the shower sump is a sniffer and another Rule 500 in the main bilge only goes on when the sump pump goes on so it's never on long enough to fully drain the main bilge. Lately it's been blowing fuses and I'm ready to just pull it all out and start over. But I'm also afraid I'll screw it up even more.
Having worked with a good boat wright for several months on the re-fit of our boat, I have learned (
more than ever) that it's cheaper and easier in the long run to just 'start over'.
While the EY surviving 'factory' circuitry on our boat is no way the only or maybe even the best answer, it is logical and straightforward compared to other boats I have helped other owners with, over the decades.
Your 32-3 has a divided-up bilge with complicated access for both hoses and wiring. This is a by product of the TAFG, and, well, "it it what it is"....
I once did regular bilge checks for a friend -- E-32-3 -- who winters in Arizona, and that whole forward multiple bilge area was interesting the way the pump intakes and float switches were arranged.
(I really like his boat, I should point out, and did a coastal delivery with that couple once. Wonderful boat in the ocean.)
Anyhooooo.... I recall that the forward pump had been changed to a centrifugal type and would easily air lock unless kept submerged in about 1.5 inches of water all the time. This was just one more data point convincing me that our stock positive-displacement pump(s) were more dependable.
As for laying out the wiring and plumbing, start with a large sheet of paper with your sketch of the boat outline looking down, and with #2 pencil and new eraser, start putting the information. Once you have sat down with the pad and your tape measure, time to overlay where you have found the existing wire runs, whether good or questionable.
My SWAG is that the original hose runs are mostly intact, because this is difficult to alter, but the dewatering devices and wiring were altered by prior owners.
At this age the boat is, in any case, overdue for new hoses, pumps, and new tinned wiring with well-sealed connectors.
(Proper way to treat those old "Rule" pumps, strictly IMHO, is to fling them with gusto and joy, over the side. Like a mortor shell, there is an optimal degree of arc to get the most distance.)
Anyhow, let us know how this goes. And, speaking of technology, unless you are good with CAD drawing, do what a friend of does and take a well-lit overhead view of his precisely-detailed pencil drafting of complex designs... with his iPhone... and then he sends the file to the customer. He is an excellent old-school draftsman.
Cheers,
Loren