FWIW... that ground wire of course provides a ground to the handlebars themselves... The Onlt thing a ground is needed for at the HandleBars, is units with Turn signals mounted to the Bars..NO other circuit at the handlebars includes the Need for a ground... they are all hot Wires...

 

And a little incidental thing like the headlight

 

Dunno the year span but stop/run switch was grounded on control systems up to 84 then they changed housings. Can't remember if the wiring did too. If it came from the factory with a ground wire logic says that it needs to be there.

 

Turn signals are the main thing...but if the handlebars are not grounded, and you get a bare wire...you can get all kinds of weirdness cause it won't pop the fuse/breaker...

If you are running turn signals on the bars, and no ground wire...all the current is going though the neck bearings, which is never a good thing...

 

As stated above the ground is to prevent the handlebars becoming an electrical path should you suffer a live short circuit on any of the handlebar control circuits for example indicators, kill/run switch, horn, lighting circuits or any other handlebar switched circuits you may have thereby providing a parallel path to possibly activate circuits that have not been selected.

 

It's strictly for the lights as the only path to ground on these post 84 to pre 96 was metal to metal.
And the forks are NOT a solid metal to metal contact.

 

Huh...all my Headlights are mounted to the top tree on FX and Bottom tree on FL... But... some have mounted them to the handlebars I suspect..

First part I agree...second not so much... most handlebars come from the Mfg with rubber isolators on the mounts... the mounts that the ground wire goes to in fact..
If yer signals work, but, you have no ground to the Handlebar mounts, then your ground is coming thru your Cables.. maybe worse than coming thru the Neck bearings... which is what happens if the Frame to triple tree ground strap is Not in place.

 

My ground hits the lower tree and there's a jumper to the riser bolt.

 

All I have encountered, have two wires.. Matters not... Grounding the Bottom tree is Paramount, the bars??? only if ya gots turn signals really...

 

I went out to the shop to check my 98 and as I thought the ground wire from the riser bolt is connected to the upper tree. There is no ground from the tree to the frame under the tanks. Parts book doesn't even list one so I guess the MOCO relies on the neck bearings to to complete the ground. I think once I'm all healed up i'll install a ground from the trees to the frame. Another thing I noticed is that no one mentioned the grounding spring in the riser. Is it really necessary? Cause I don't have one (never did)... I would think the bar clamp and the hatched bars would be more than appropriate... On another note, I would have to agree with Tom that if it's not groundded how would you know if one of your switch wires is shorted? Maybe when you mount the bike and grab the bars you'd get a little tingle. WooHoo.....