Mystery Plug

[Gallaecus]

check your serial number for engine. is it an 80 G ?

sometimes there is a tag on the harness that will identify it.
I think you are not reading the wire color correctly.
if you have the manual..sometimes you can identify a harness
by the wiring to the lights....

not sure I have seen a black/yellow wire
and light blue is called sky blue in the book and it is the neutral indicator.
sure those aren't red/yellow

try to identify your harness so you are looking at the correct diagram.

[crazy steve]

I'll agree, it looks like you have a XJ harness, or possibly a LH harness; these had some of the same interlock features but they don't show up on the wiring diagram unfortunately. The black/yellow would go the the clutch lever switch, the blue or gray to the neutral light. Try grounding the blue with the power on and the bike in gear (light off); if the neutral light comes on, that's what you have. If you knock out a fuse when doing this, you still have more of the 'safety interlock' wiring connected in the harness, you'll have to track that down too.

If not, connect the two red/white wires together and ignore the other two and you should be good to go.

[cywelchjr]

I'll agree, it looks like you have a XJ harness, or possibly a LH harness; these had some of the same interlock features but they don't show up on the wiring diagram unfortunately. The black/yellow would go the the clutch lever switch, the blue or gray to the neutral light. Try grounding the blue with the power on and the bike in gear (light off); if the neutral light comes on, that's what you have. If you knock out a fuse when doing this, you still have more of the 'safety interlock' wiring connected in the harness, you'll have to track that down too.

If not, connect the two red/white wires together and ignore the other two and you should be good to go.

With an 81 harness it may well have the interlock parts of the harness which may be what is keeping it from working, as the starter circuit is interrupted without the clutch switch (I don't believe the XS's had the side stand switch, that being XJ only.

[Yard Dogg]

I don't know how much wiring experience you have, but it might pay just to unravel it and rewire it according to the diagram, or just send it back. Do you still have your old harness?

[Bassman]

Well, I know a lot more now than I did when I started, but I wouldn't classify myself as an expert at all. Unfortunately, the old harness was stripped way down by the PO in order to cut out all of the "unnecessary" parts (turn signals, speedometer...etc).

[Yard Dogg]

Well, it gets messy for sure when you unravel it. I just rewired my XJ to get rid of the safety features that can leave a guy stranded, but I kept my turn signals. As you unravel it, if you put a wrap of tape around all the places that branch out, then you can expose all the wires and keep it together. I completely unraveled it, cut all the factory crimps, then pieced it back together in smaller chunks. I had to cause I moved my fuse panel to the gauge pod.

Is it your starter button that isn't working?

[Bassman]

I thought it was, but it turns out the starter solenoid wasn't clicking. I checked for continuity from the starter button wire to ground and there was continuity, so I moved onto the solenoid.

At first, I wasn't getting any voltage to the starter button and then I traced the wires to this mystery plug.

[Yard Dogg]

Connect the 2 R/W together and check your ignition fuse. If the fuse is good and it still won't start, check continuity between the Br wire from your ignition switch, and the fuse, then the R/W that you just hooked together. If it gets power but won't start, then test your stop switch. The 2 R/W wires you've just hooked together should run directly through the stop switch, then to the starter solenoid. The stop switch only disconnects when you push it. It should have continuity when in run position.The Sky Blue, and B/Y shouldn't need to be hooked up because you have no clutch switch.

Look on this XJ manual under wiring/diagram to see what I'm talking about.
http://www.ringler.us/xs1100/XJ1100ServiceManual.pdf

[DGXSER]

I woudl agree it sounds like you have an LH (which is an 81 Midnight Special) or XJ wiring harness. Although, on my 81 SH, the clutch switch is wired in.

Try this as a simple solution before you go cutting and unraveling wires, take a jumper wire and put it between the two red/white wires. Turn the key on, step one, see if a fuse gets blown, not blown fuse, hit the starter button, no blown fuse and starter turns you know what you have. Put some conncetor ends on your jumper to permanently install it and wrap electrical tape around that to secure it all nicely.

Next step, go for a ride before consuming way to many beers!!

[Bassman]

Well, I connected the two r/w and no blown fuse! So I spliced them and all that's left is changing the oil and attaching the gas tank.

Thanks for all the help gents