CB350 - Wiring Concerns

I'm building a wiring harness for a 71 CB350 using 18 gauge wire from british wiring. I ordered a length of every color used in the stock harness but I'm wondering if I should go with 16 gauge or larger for some sections. Here are the areas I'm most concerned with:

- Headlight using a 35/35w bulb. The headlight circuit runs through the RH Switch, to the LO/HI controls of the LH Switch, then to the headlight. I've heard using too long of a run can be problematic, but I want to keep my headlight switchable.

- The yellow and white wires coming from the stator. These will be spliced together for the 'always on' charging mod. I'm worried it could overheat coming from two stock 16ga wires to a single 18ga. I'll be using a R/R unit from Sparck Moto.

Also, is there a significant difference in watt usage/charging between a bike wired fully with 16 gauge wiring and one using all 18gauge?

If you're worried about your 18ga wire being too small for some applications you can always run 2 wires together (seeing as you already have it).


And with your headlight, you can use a relay if you are worried about losing current.

18 gauge wire has higher resistance than 16 gauge, so you may lose a little power to some of the components. For our harnesses, we use 18 gauge for most runs, but I upgrade to 14 gauge for the charging system, ignition system, and headlight. Like hillsy mentioned, you can also run two wires together if you can't (or don't want to) get wires of a thicker gauge.

Sonreir™ said:

18 gauge wire has higher resistance than 16 gauge, so you may lose a little power to some of the components. For our harnesses, we use 18 gauge for most runs, but I upgrade to 14 gauge for the charging system, ignition system, and headlight. Like hillsy mentioned, you can also run two wires together if you can't (or don't want to) get wires of a thicker gauge.

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I think I'll follow suit, thanks Matt.