Originally Posted by rmhrc628
Is there any guide on what gauge wire we should use when adding accessories ?
Is 12 gauge the universal across all the brands ?
I want to add in some wiring and can't seem to find what size wire is stock on my Hondas
12 gauge? Whoa! That would be fine if you're adding a microwave oven!
Frankly, most accessories on a bike can be fed just fine with 20-gauge or 22-gauge but that size wire is not robust enough for the physical abuse it goes through on a bike. Ya know, vibration, wind, rain, hail, rider fiddling, etc. I use 18-gauge for most everything, and bump up to 16-gauge for anything likely to pull 10 amps or more, like a horn or heated grips. Here's a typical AWG chart and you can see it says 18-gauge is fine for 3-foot connections up to 40 amps (that's 480 watts!)
So, 18 and 16 gauge works fine, I'm also careful to use lots of wire ties to hold everything in place, and I wrap electrical tape around my wires if they are going to be routed over anything with an edge or corner -- to protect them from rubbing damage. But electrically, the amount of copper in an 18-gauge wire is plenty for bike accessories.
The only exception I'd note would be the connection between the battery and a aux fuse panel, if that's what you plan on having. For a 60-amp aux fuse panel, I'll use 12 or 14 gauge, just for overkill.