can I join 2 different size wires?

Rate this post

Hi James, I?ll try to answer some of your questions.
Am i risking damaging the acessories or blowing breakers by using this larger wire? all of my breakers are 10 Amp.
No, you?ll not cause damage by oversizing wires. Breakers (or fuses) should be sized to the weakest link in the circuit. The 10 amp breaker size is suitable for most loads suitably fed from #16 wire. Please note that negative wires must also be of adequate size as they?re protected by the same breaker that protects the positive wire.
Also in some cases I have run several grounds back to a common ground or several light to 1 positive wire I wanted to know if when I do this Am i supposed to use the same size wire that the acessories calls for or should I be doubling or tripling the size in the case of running two or three lights to one positive?
As poconojoe said, to know what minimum size wire you need, you need to total all the currents by every accessory connected common to that wire.
also curious to know whether or not joining my ground wires is a good idea?
Not sure what you mean exactly, but the number of joints should be minimized wherever possible. Making additional joints to allow use of several pieces of wire to get adequate length creates additional future failure points. Depending upon where you?re using your boat, trading safe reliability for economy may be unwise.
do I need to have A ground running directly to the battery for everything assesory or can I join groups of assessories or even all of them 21 common ground? I am installing bus bars just before the battery just haven’t gotten around to it.
I wouldn?t run separate negative wires to the battery. Use a common bus bar or splitter located at a convenient location and then connect the bar to the battery via a wire large enough to carry the total current of all the connected accessories.
OK. I?m gonna stick my chin out about a couple of additional things. Unless you?re boating around salt water or if the boat sits continuously in dampness near the water, tinned wire is not a necessity. My 43 year old Starcraft has numerous untinned original wires and there?s no evidence of corrosion anywhere, including where the bare copper is exposed. That said, I recommend coating every joint and terminal with a dielectric grease or sealer to avoid the potential of corrosion.
A second point is that many folks take the approach that breakers and fuses only protect the wires, not the devices that the wires feed. This is a principal that can be taken too literally. It may be an accurate statement only if wires are not unduly oversized, since components also require protection. The manufacturer of a component often recommends a maximum fuse size without knowing what size wire you?ll be installing. Just because you used an oversized #10 wire to feed your fuel gauge is not justification to use a 30 amp breaker to protect the circuit. – Grandad

You are viewing this post: can I join 2 different size wires?. Information curated and compiled by along with other related topics.


Please enter your comment!
Please enter your name here