Ok, so my 27 had a single “on” or “off” switch and two batteries. I believe the second was added after the boat was built and it is just wired in parallel to the first battery.

I went to correct this with a normal “1, 2, both, and off” switch. Of course I took it apart back in early June and am just now getting it out back together. My question, which of the circuit breaker power wires under the seat need to be wired hot to a battery terminal and not the common or feeder on the switch? My only concern is the bilge pumps working if the boat is left in the water and switch is off. Am I over thinking it and the switch just needs to be left on one battery or the other if it is kept in the water? Or can I hook up the cockpit power wire direct to one of the battery terminal wires on the back of the switch for it to run bilge pumps of the auto floats kick on? I’ve in the past on full rerigs just connected the auto float wire direct to the back of the switch on a battery post to keep the install clean but not sure if everything else is set that way.

For what it’s worth the harness going to the front seems unmolested and boat still has original switch panel and dash.

Unable to say which wire under a seat needs to be wired hot, but in simple terms, the bilge pump needs to be wired direct to the battery. Can also be connected at the switch so long as the switch will not turn it off

Make sure it is fused at batt

the wired that would hook to the switch under the seat have circuit breakers right there.

sorry not following what you’re saying there. I’m just saying if you run a constant 12v supply to bilge pump make sure it is fused. If it’s all ready set up that way great.