Wiring woes

Just spent most of the day chasing down why my tail lights and horns don't work did not find anything obvious bit found a few suspect earth wire connections and wriggled and pulled a few plugs and they ( Lights) started to work. So I move onto the horns, with the horns off the bike they worked when I put the horns back on the bike they didn't. I know horns are turned on by opening and closing the earth side of the circuit, not sure why they do this but any way after pulling the handlebar controls apart to check the horn switch which was inconclusive, I gave up for now on the whole exercise, so I still don't have a horn or tail lights. While I was fiddling with the horn and indicator switch assembly I noticed a switch mechanism on the clutch lever what's that about? Any other advice on the horn or tail lights would be much appreciated

 

The switch mechanism on the clutch is possibly part of the safety, which allows you to start the bike whilst in gear but only with the clutch pulled in. On my XJ if its in gear and you try and start it wont, but pull in the clutch and she's away. Sorry cant help on the horn/lights side of things.

 

Thanks z32800 suspected something like that my bike will only start in neutral so a PO has probably disconnected it, the bike also will start with the sand down which has caught me out a few times.

 

If it starts with the sidestand down, somebody has bypassed the sidestand switch. If it won't start in gear even with the stand up and the clutch lever pulled in, somebody has messed with the clutch lever interlock switch. The fact that it still insists on being in neutral to start means the safety relay is still there but only partially doing its job.

Honestly, I'd recommend fixing it. The safety interlock system seems like so much frippery on first impression, but it's actually quite a good idea. I've forgotten on occasion to pop the sidestand up (usually because somebody is standing next to the bike babbling at me while I'm getting ready to go) and I appreciate that it will immediately shut off when I drop it in gear rather than let me ride off with it down.

Stall the bike in traffic once when you're in say, 4th gear and you'll quickly appreciate the utility of the clutch lever override.

Here's a little photo-feature on the clutch lever switch: http://xjbikes.com/Forums/viewtopic/t=30354.html

 

So if the stand is down the bike should not start.if the bike is in gear with the clutch not engaged it should not start but if you pull the clutch in it should start even if in gear. It worries me why a PO would disconnect this stuff.

 

Correct on the latter part as long as the stand is up.

The reason most people disconnect it is they start having a problem with the sidestand switch causing intermittent shutting off. Because of its rather inhospitable location, it's usually the first point of failure.

Clutch lever switches tend to self-destruct as noted in the piece I linked to.

 

here is a page out of the XJ750J Service Manual....

 

Notice that while the sidestand switch is called out (#10) and #4 is "from sidestand relay" that there is no mention in the text of the need for the sidestand to be up?

Factory books are a hoot sometimes.

 

Finally got to the bottom of this problem after many hours of searching and testing. it turned out to be a wire had broken off in the ignition switch mechanism. Through this I discovered that if you turn the switch fully anti clock wise and go one click past the point where it locks the steering it will turn on the park lights and let you take out the key. Good way to flatten the battery if you are not aware of this. Also I did not find a fuse for this circuit at all. I wonder if it uses the head light circuit fuse.