wiring..old versus new

[rdmcguy]

Hello,
I have decided to transform my 78 standard into something a little more modern .
Will be installing a newer front end and would like to use the handlebar switches , but have discovered that the wires are much smaller,
I have no problem grafting on new ends but am uncertain the smaller gauge wires will be sufficient to carry the current.
Without knowing how to measure the gauge,
I can only guess that they are 20 or 22 gauge.
Don't want to fry anything.
Thanks Joe
Build thread to follow.... Code name EL TORO

[IanDMacDonald]

I've completely re-built three different wiring harnesses and upped the wire gauge a few sizes just because I got a good deal on the colored spools at the time. I always recommend it, but I'm sure the wire will handle whatever just fine, considering the fact that even small 20 ga. wire can handle a max of 11 amps.

[DGXSER]

Its all about the load. You will want to see what switches and such your using and what load is on them. Generally speaking your probably fine. But a few items like say the stop run switch on the right hand controls is taking a lot of the load of the bike through it.

So, pay attention to what loads your putting through the wires and the switches. That's the best advice I can give you, I ain't no sparky genius.

[crazy steve]

The OEM manufacturers rarely use wiring that's bigger than needed, so if the 'new' wire is smaller you'll likely have issues. And are the switch contacts in the 'new' controls rated for the load? A lot of the modern bikes use 'black boxes' for switching (basically being electronically controlled relays) so the switches themselves are very light-duty. It will no doubt work at least for a while, but long-term durability may not be there.

The wire sizes Yamaha used on the XS are already a bit small for the loads, smaller will cause more voltage drop.

The other thing that should be mentioned is the OEM XS switches are all make-or-break (i.e. you turn it on or off with maintained contacts), a lot of the modern switching is momentary contact; you press the button to send a signal, then release. The 'box' does the switching.

...small 20 ga. wire can handle a max of 11 amps.

Twenty gage wire can only handle about 4 continuous amps....