sorry about that short, incomplete comment. i was at work. switch ground is the preferred choice in 12v electrical circuits. very few if any switch positive. a quick google search will explain it, but use switch ground in your circuits.
oh yeah most of the circuits in our boats don't even need a relay just use the switch to operate it. carling switches can handle most if not all amps. when my dash switches go I'm just gonna buy a carling dash switch kit and rewire. i was able to toss ALL of my stock ballast electronics (switch panels, decc, relay block , CAN bull crap) when i installed my new ballast system. works like a charm. havent had a problem yet. and it really cleaned up the mess under my dash
Yes Toyota really blew it on this one. They should of stuck with the KISS method (Keep It Simple Stupid)