XJ700 Wiring Losing Contact somewhere.....

My 1985 700 airhead is having a little electrical/wiring issue. What is happening is that when turning the handlebars to the right, the headlight and neutral light go out on my bike (front turn signal low beams aka the "driving lights" remain on), should you try to start it when this happens and all you get is the oil light comes on, starter doesn't engage or anything. If you reach down in front and grab the wire harness where it runs under/into the headlight bucket and you fiddle with the harness's positioning, you can make the headlight and neutral lights turn back on and the bike will start properly. If the engine is already running all that happens if you turn the handle bar to the right is the headlight turns off, the bike will not stall, which leads me to believe that whatever is frayed is shorting the headlight and neutral safety switch out? If you turn the handlebar far enough back to the left (usually halfway to the left "steering lock", they will come back on, but this leaves wide open for driving without a headlight, a ticket I would rather not get...

Which wire should I begin looking at? Obvious has something to do with the connection right under the headlight bucket.

 

I can suggest to start at headlight and follow every single cable to next the connector where it goes.

 

The yellow wire inside the headlight bucket about 2 inches out of the bulb plug had a small fray in it, my bet was that when turning the handlebars to the right, it cause the wire to push into the headlight bucket and short out, fixed that, I'll get back.

 

That's good. IN those old bikes you have to check every single wire

 

And it's not fixed, couldn't find any other obvious issues. *sigh* I'm tempted to rewire this thing from scratch because the wiring has been tamper and tampered with and I hate the clutter inside that damn bucket...

 

The clutter won't go away; it's a Yamaha factory-installed feature, and every wire there is needed. Check Ebay for a used harness. It'll save you a lot of time.

 

Just out of curiosity, why are there so many freaking wires on this bike?! You would think that with having a wire harness like an inch and a half in diameter that the bike would be fuel injected or have ABS or something. I see an older bike like these being technology ridden having may 10-15 wires tops. Instead there's freaking 30 (probably an over-exaggeration). Seriously, the Kawa I picked up on Friday has like 6 wires; I know it helps that it has old school point ignition, but damn I don't think having electronic ignition would reguire more wires than fuel injection!

 

Just out of curiosity, why are there so many freaking wires on this bike?
because of the relays.

I think you are looking for a grounding problem or open connector connection. if you had a shorting problem you would be blowing fuses.
check the crimps at the connector and how well the connectors mate inside the shell.

does the head light go out in low AND high beam?

look at the the 2 circuits seperatly



you could do a minimal wiring

 

1. Safety circuits to do things like cut the ignition if the side stand is down in gear with the clutch engaged
2. Self-cancelling turn signals
3. Headlight relay to reduce load on the electrical system while cranking
4. Electric start (is your Kawa a kickstart?)
5. On some models, like my '82 SECA, integrated monitoring for things like burnt out tail and stop light bulbs, headlight, fuel level, oil level...
6. And, yes, transistor controlled electronic ignition with variable reluctance pickups that work much better than points

 

Safety circuits are understandable. My Kawa has a neutral safety, but that just shows you if you are in neutral, it doesn't stop the bike from starting. You can start it with side stand down, in gear, without pulling in the clutch lever and the bike will roll forward (guy even has evidence of this on YT). My Yammie doesn't have self canceling signals. And the Kawa is kick and electric.

They go out regardless of high or low beam.

 

check the blue/black wire in the control for high low beam and the red/yellow wire from the head light fuse to the control. also check the ground for headlight with a test light or meter as you turn the handle bars
trace the brown wire from the signal fuse for the neutral light another member found the brown wire had broken inside the insulation near where it enters the harness

do you know if the meter lights fail as well?

 

I'm pretty sure your 700 ORIGINALLY had self-cancelling turn signals. It's not unlikely that a previous owner who didn't understand how they were supposed to work removed them (possibly by installing an aftermarket speedometer), or that there's another bad connection somewhere that's preventing them from cancelling.

Both my '82 XJ750 Seca and my '89 XV750 Virago have self-cancelling turn signals.

 

What is the meter light?

What exactly does "self-canceling" mean for the original application on these bikes? I haven't played around with the push for one second, push for two seconds, etc. that some aftermarket units do. My turn signals. from the last year of experience, you push the switch to the desired side, the switch centers, but the lights continue to flash until you push in on the selector to turn them off.

My bike does not have the original cluster either, so it is entirely plausible that they were removed; the gauge set has been replaced with that of one from a 650/750 model.

 

speedo tach cluster meter lumination lights, oil light, turn signal light, high beam light

self canceler shuts off blinkers after bike travels a certain distance. the unit is about 3 inches long under the seat

 

Close. Actually, the self-canceller shuts off the turn signals after a certain distance (150 feet?) AND a certain amount of time. The reasoning is that, if you're at a light, you don't want it to shut off while you're standing still, but, if you're changing lanes on the highway, 150 feet goes by really quickly.

Also, on the Seca, at least, the unit is under the tank, and is not that big.

 

I'm not sure if I have them any more then. I personally have gone around 2 miles on the highway with the signal still blinking cuz I was an idiot and didn't turn them off.

 

box on right is the self canceler should be under the gas tank on the frame
box on left is the diode block #45 which is part of the neutral light circuit as well as other circuits
hook a meter to your headlight wires
do the ground first in the connector then see if you can move the wires at the cable harness bracket to simulate the problem
thats where the most stress is going to happen , bring the connector out side the bucket and start bending the cable to the right
working your way down .
the neutral light #27 will be more difficult because it is in the cluster

does your head light turn on with the key or when the bike starts?
I see on the wiring diagram that both fuses are run off the brown wire that goes from alternator to key switch
you may want to look at the key switch connector

 

The lights turn on with the key. Is the key switch connector hard to get to? Could it be possible that it's the ignition switch itself? Sometimes I have to fiddle with the key to turn the ignition on.

I don't have that either of those that I have seen. The only thing under the gas tank with wires running to it is the 41R-71 flasher relay.

 

Diode block: under left side cover, above regulator.
sorry for the mislead you do not have a seperate
Turn Signal Self-Canceller Relay:
NOTE: all XJ700 models and XJ750-X models use a consolidated relay assembly (mounted under and to the rear of the fuel tank, on the wishbone frame triple-tube joint) which combines the turn signal flasher, the turn signal canceller relay unit, and the starter circuit cut-off relay.

the ignition switch is easy to remove and clean up it 2 bolts and some extentions to reach the bolts
Clean and lube the ignition switch

 

So is the diode block the same as the safety switch relay, so to speak? There's a relay under my seat that I have to unplug in order to start the bike with the kickstand down (even with clutch in and in neutral). The only issue I'm seeing with that is that my relay has wirings leading to it (as opposed to wires coming out of it) with a connector and the relay connects into the connector.

 

Sorry if I'm just throwing us in circles. There's too much happening on this bike in terms of electricals and wiring; it's just ridiculous. I don't even think my '80s Honda Civic (carbureted engine) had this many wires...maybe it was just a lot cleaner looking and not just wires thrown everywhere... If I get serious with finding out this issue, I'll just bring it down to my mech/electrician and have somebody who's willing to tear the bike apart look at it.

 

no the diode block is part of the starter relay and and dash lights it is needed to maintain grounds or voltage.
your sidestand safety switch is not working you need to fix it or "test it"
this link is about switches and relays and diodes
http://www.xjbikes.com/forums/threads/the-ultimate-relay-switch-sensor-and-diodes-guide.27543/

it states
Sidestand (kickstand) switch:
- twist the two (or three, depending on the model) wires together and ground them. Grounding the wires is the only way to complete the circuit that activates the sidestand switch relay.

Sidestand (kickstand) relay:
- unplug the safety relay which disables the whole bloody mess but DO NOT leave it that way, fix it right!

the above are not related to the problem your thread is about

 

first I do not think the diode block is your problem but you asked about it so
the diode block
I will explain the starter relay #39 in wiring diagram.
voltage comes from ignition switch to fuse #4 to kill switch #5
travles to coil in starter relay #39 then if bike is in neutral the voltage travels to diode block#45 through the neutral switch #26 then to ground. the relay closes, neutral light comes on. Push starter button# 36 ground is made, solenoid activates#40 starter engages bike starts.
if not in neutral, clutch safety switch #37 comes into play bypassing diode block sends voltage to ground through side stand safety switch #43 if side stand is up which closes switch, press start bike starts.

note.bike will stall if put in gear with side stand down

so why does the neutral light connect between 2 diodes in the block you ask?

if you pull in the clutch while bike is in neutral the clutch switch becomes the ground for the starter relay through the side stand switch bypassing the neutral switch because electricity takes the easiest path to ground ( not through the diode).
the neutral light is then grounded through the diode block to the sidestand safety switch keeping it on to tell you the bike is still in neutral

so the diode block controls safety lights and starter relay.

my head hurts now...
the oil level light # 26 also connects to the diode block then to the starter button that is why it comes on when you press the starter button so you know the light works. when you low on oil the oil level#24 switch closes lighting up the oil light telling you you are low on oil.
broken wires with intermitent contact are labor intensive to find $$ at the mechanics shop
you need to use a multimeter and wiring diagram to trace wires while trying to simulate problem or rewire the problem areas.
I have a wiring diagram with part number key and wire colors if you need it start a conversation with me with your email and I will send it to you it is a word doc. your mechanic will need it if you go that route

 

I'm not gonna worry too much about it for now. I'm shoving my XJ on the back burner because I fix one thing, and another things pops up, which I am honestly getting quite tired of so now I'm seriously debating selling my XJ. I just can't afford it. What started out as a $700 bike + $150 for the starter + a carb clean to get it running has quickly turned into almost two grand spent on this bike. When I look at it that way, that's almost than half of what some of the new bikes I'm looking at cost, which could've made one hell of a down payment.

Right now, I'm focusing on getting my KZ400 road ready. I bought it for $500 and it's already a better behaved bike only needing an air filter, front tire, headlight, chain and a carb balance; most of which has already been taken care of: air filter, chain and carb balance are done. Now I just need to save up some money for the front tire swap (already bought the tire) and stop being lazy so I can switch the headlight bulb.