Help with Accessories Wiring
Hi so I'm having some issue figuring out if i have what i need to wire up some lights and an air compressor. I am looking at adding a fuse/relay box to help keep wiring a little cleaner.
The Front light bar i plan on using is 126W and from what figured i will should use a 15 amp fuse and 30/40 amp relay and run 10 gauge wire. The toggle switches i have are 20 amp.
I will be mounting two smaller lights in the rear totaling 18W so i was going to run a 2-5 amp fuse and 30/40 amp relay with 10 gauge wire. The toggle switch i have are 20 amp.
The air compressor i have has a 20 amp draw so im assuming i ill need a 20 amp fuse and could get away with using a 30/40 relay or do i even need a relay in the compressors wiring? I assume using 10 gauge wire would be fine for this also. The toggle switch i have is 20 amp.
Any words of wisdom would be great.
As Aaron pointed out, 10ga wire is overkill for the lights. I frequently use the online calculators to figure out a safe wire size. for DC circuits, what you are normally doing by using larger wire is decreasing the voltage drop along the wire. The more voltage sensitive the device (like radios might be) the more benefit you would have from oversized wires.
Are you planning on using high beams or reverse to trigger either of these lights? It is a nice feature to have, but adds some complexity to the wiring needed.
I tend to use relays for anything over 5 amps, or anything I want triggered by another vehicle system (such as factory lighting). I also fuse everything as close to the source (battery and distribution block) as possible. I have made a few mistakes and burned up wires before, it's not fun.