Ground Wire

[Crossrodes]

I just noticed in a picture I took before I took my '79 apart that I had a ground wire attached to one of the studs on the rear coil.  Can anyone tell me what the other end of this ground with is attached to?

[Bob_Roller]

I don't have a bike with two coils, but from what I've seen in comments, the main grounding or earthing point for the electrical system is somewhere on the forward coil mount .

My best guess that the wire from your coil ends up somewhere at that point .

Is it a solid brown wire, or some other color ?

There should be a black wire on one of the coil terminals, it is the wire to the tachometer .

[Rob Valdez 79 R65]

Here is a wiring diagram for a '79:

http://www.pbase.com/tomfarr/image/121670650

[Lucky_Lou]

Mines a 79 twin coil i will check it out for you next week as the bike is tucked up in the workshop, but as i recall the brown is always earth.
When i did the rebuild i had a problem with wiring to the coils and both the Clymer and Haynes manuals diagrams didnt match to add to the confusion.
Lou

[Crossrodes]

Here's the picture of the wire I'm talking about.  You can see it's a black wire and its grounded behind the stud holding the coil.   Looking at the bike now the only wire I can see that would fit goes from the battery negative post to a ground point on the transmission.

Rob thanks for the wiring diagram but those diagrams do not show the actual physical ground point connections.

[Lucky_Lou]

That looks like the main earth wire for the battery and should be connected from the -ve terminal to the bolt securing the speedo cable on the gearbox.I will put a picture up as soon as i can but maybe someone else can confirm this.
Lou

[Crossrodes]

I thought it might be that Lou.  I connected it to the gearbox when I rebuilt the bike.  So somehow I did something right when I did the rebuild.

[Rob Valdez 79 R65]

Yes - that is the main ground going to the battery.
The idea behind moving it is twofold:
1) to avoid stripping the aluminum threads in the transmission vent bolt
2) to get a more direct path for ground to the starter, but this location doesn't really accomplish that.

Thanks for the picture.  I never would have guessed you meant the main ground!

[Rob Valdez 79 R65]

That looks like the main earth wire for the battery and should be connected from the -ve terminal to the bolt securing the speedo cable on the gearbox.I will put a picture up as soon as i can but maybe someone else can confirm this.
Lou

Yes - check and see if you have this wire, here:

[Lucky_Lou]

Nice photo Rob but wheres the speedo cable
Lou

[Bob_Roller]

He's got a Vapor instrument cluster .

[Crossrodes]

Rob, thanks for the pic...yes that is where it is now connected.

[Rob Valdez 79 R65]

Nice photo Rob but wheres the speedo cable
Lou

I use my GPSr for a speedometer.