More wiring/ electrical issues..

[motoman]

I was stating Green/ Brown from memory (only a couple cells left in the brain) it was indeed Green/ Black the reading was nill. If I'm then reading right the coil is bad. BUT the bike runs.. Can it run with bad coil?
The manual says to check voltage at the battery in mine on 6-20 having done that at the battery and revved to 2K I was getting LESS voltage than with the engine off. (off- 12.9) (revved 2K- 12.4) as for the white to white can't remember the reading but it wasn't any where near .37 Ohms.

Before any testing would have any validity, all electrical plug-ins(even if not sure what circuit they operate) AND grounds should be removed, cleaned and re-connected. There's five of those alone that are behind the fuse panel mount, and several chassis/frame grounding locations. Ignition switch and kill switch contacts ARE the most notorius locations for voltage losses elsewhere.
I would suspect the XJ having similar issues, as is the case with majority of any 30+yr. old scoot.

[MetalMaxx]

Disconnecting then..

That sounds definitive, and will be what I do on the morrow then. Disconnecting and cleaning all the things in all the places.
Thank you.

[CaptonZap]

QUOTE=MetalMaxx;455889]IIf I'm then reading right the coil is bad. BUT the bike runs.. Can it run with bad coil?
as for the white to white can't remember the reading but it wasn't any where near .37 Ohms.[/QUOTE]

The alternator coils have no bearing on the engine running, since the battery supplies current to the ignition system, and as long as there is enough voltage in the battery, the engine will run. What won't happen if the alternator coils are bad is the battery getting any refresher voltage, and eventually the battery gets run down to the point that the engine quits.
When you say " wasn't any where near .37 Ohms", what do you mean? Near more, or less? Did the meter, and I assume you have a digital meter, remain in it's original reading when you touched any of the two white leads, did it go to zero, or what ever it read when you touched the two leads together to see if it was working, (and you did do that, didn't you?), or did it read lower by a 20% or more than the .37 ohms that it was supposed to read?
Did you put one lead on the engine case, and the other on one of the white leads and check for continuity?
There should not be any, from any of the white leads to ground. Just the.37 ohms between any two of them. If you have continuity from any white lead to ground, the coil is shorted internally, and you need a new stator. If you don't get the .37 ohms +/- between any two of the white leads, that coil is open, and you need a new stator.
A lot of electrical trouble shooting is visual. Someone poked a coil with slipped screwdriver, the insulation got hot and cracked, allowing a wire to touch ground, one of the coils has insulation that is REAL dark brown or black, etc. The list is long, but all of them can be seen with the naked eye. Give every component a good inspection, not "yeah, there's the wire and connector, they must be good". Where the wires go through the case is another chaff point, and the rubber grommet might have gone to hell and allowed the wires to rub. Get a bright light and start looking. A magnifying glass if you're old like me.
Let us know.
CZ