12v accessory over 1 wire

(posted in wrong subforum before going to try and remove it)

Hello all,

Newby here to arduino. Looking for some assistance on programming and wiring an arduino setup to control multiple 12v accessories

Basically here it is. I have multiple 12v accessories on my truck (led lightbars mainly) and everything is hard wired to the point of almost multiple wires per accessories and now I'm trying to clean it up. I feel there is a way to have 2 arduinos on my truck. 1 in cab and one in bed, with multiple switches (or a touchscreen later on) on arduino in cab with a data and ground wire to arduino in bed where the arduino in bed can turn on the various devices based on what switch was initially pushed. Goal is to reduce the number of wires. I would like to have a strobe function available to certain devices and maybe control over rgb leds, from what I've read so far I'd want mosfets instead of relays.

Looking for some guidance on what hardware I'd need and why So I can look into it some more and post back with questions.

Thanks,
Steve

Ps if I'm in wrong group I apologize

Why not 2 wire, I2C? Lots of I/O boards available there.

I read elsewhere on forum that 1 wire was ground and dateline. Is that what you mean by 2 wire? I'm open.to ideas I just don't want what I have now a bunch of wires

No. I2C uses data, clock and GND.

But we are looking at a significant distance here. I2C would probably not be advisable. RC485 more likely.

That is 2 differential wires plus a protective ground.