I discovered that my ground cable that runs from the battery to the frame is waaay too small. Itsthe steel braided type. So with that said, is there a preferredwire size and a preferred grounding location ?

Thanks Ben

 

What model?

My 84 FLTC has a steel ground strap connected from the inner primary to the frame crossbar.
It's the one original electrical part still worth $.02

The positive battery post goes to the solenoid and the negative post groundsat the starter mounting bolt.
Both of these cables should be copper. If you're using braided steel from your battery I'd change it.
My local Indy made my cables sized from the originals.

 

Here is the information I have for my Sportster build. I believe it is all in metric though:

The following wires are 44 / 0.30 , 3.00mm 2 , 27.5 Amps
Red ........................... rectifier/regulator to battery.
Red ........................... battery to main fuse.
Red ........................... main fuse to ignition switch.
Red with white tracer ......... ignition switch to the three other fuses.

The following wires are 28 / 0.30 , 2.00mm 2 , 17.5 Amps
Yellow ........................ Alternator to rectifier/regulator.
White ......................... fuse to lights sw.
White with blue tracer......... lights sw to high/low sw.
Black.......................... earth connections to frame.

The following wires can be reduced to 14 / 0.30 , 1.00mm 2 , 8.75 Amps if preferred.
Blue........................... fuse to kill switch
Blue with white tracer......... kill sw to coils and electronic ignition unit
Orange with red tracer......... fuse to brake sw to brake light.
Orange with white tracer....... fuse to switch to horn.
Orange ........................ fuse to flasher then to indicator switch.
Orange with white tracer ...... indicator switch to left indicator lamps.
Orange with black tracer ...... indicator switch to right indicator lamps.

The following wires can be reduced to 9 / 0.30 , 0.65mm 2 , 5.75 Amps if preferred.
White with green tracer........ lights sw to speedo
White with red tracer ......... lights sw to tail light.
Red with black tracer.......... starter button to starter solenoid.

orange with blue tracer ........ neutral light.
Orange with red tracer .......... oil warning light.
Other wires as required such a water temp gauge, radiator fan etc.

 

Ben
check out thisa tread on Yooper cables
https://www.hdforums.com/m_69440/tm.htm

 

I use 3 ground cables on my bike, both are size #4 wire. I ground my battery to a good ground under the seat, I also ran a second ground from the starter.