Help! No neutral light/no headlight, no start

Since your bike is a 1983, you are faced with some of the most complicated starting interlocks ever known to mankind. A clear case of Yamaha engineers with too much time on their hands.


I have an 83 heritage Canadian model, I can't remember if the side-stand switch is incorporated in the Canadian models. I'm pretty sure it isn't because i remember riding off, one time and caught the side-stand on the road and thinking how lucky i was to be still upright.

Bike is in NZ and i haven't had anything to do with it for years.
 
Hey Scott, I'm having the same problem as you. RetiredGentelman was helping me try to figure it out. (Thanks Again) I'm suspect of my neutral switch now. I have the safety relay bypassed for the time being and when I tried to start it, it was in gear. After I put it in neutral and tried again, no lights, no start. Wondering if I somehow messed up the switch by starting it in gear. I have no neutral light so I don't know if that circuit is hot. I'll have to test and see. Weekendrider says that the neutral light/circuit has to be on for the TCI to work so if the switch is broke the bike won't fire.
My question is, what turns on the lights when the engine turns over. My thought is that there should be a relay somewhere that energizes and stays energized until the key is turned off. With my bike I don't think even the handlebar switch turned off the lights once they were on, it had to be the key. If I could find this theorized relay circuit and it's necessary inputs I'm sure I could narrow down the problem. I haven't yet been able to find an answer on what keeps the lights on. And i'm not so good with the wiring diagrams to figure it out myself, but i'm sure this same circuit gets power to the plugs one way or another. I'm going to continue to poke around for solutions. I'll let you know if I meet with any success.
 
Holy mackerel, guys. We finally got her to go.

The problem was a very dirty and loose connector off of the main harness. With the key switched on, we pulled the main harness connector. It was totally dirty, so we cleaned it, put it back together and presto, she was alive.

So the morale of this story is, check all your connectors before anything else when chasing electrical ghosts.

Now I'm still puzzled because the neutral light still does not come on. We tested the bulb and the bulb is good. It doesn't stop me from riding, but it is annoying as hell trying to find neutral.

Another thing, somewhat unrelated; My speedometer is fluttering and totally unreliable. I hooked the end to a drill and the problem isn't the speedometer itself since it tracks the varying RPMs without issue, and doesn't flutter or anything. What do I call/where do I get the part that fits inside the wheel? I think that gear may be all chewed up and giving a false readout.

Thanks for all your help again, ride on!
 
Holy mackerel, guys. We finally got her to go.

The problem was a very dirty and loose connector off of the main harness. With the key switched on, we pulled the main harness connector. It was totally dirty, so we cleaned it, put it back together and presto, she was alive.

So the morale of this story is, check all your connectors before anything else when chasing electrical ghosts.

Now I'm still puzzled because the neutral light still does not come on. We tested the bulb and the bulb is good. It doesn't stop me from riding, but it is annoying as hell trying to find neutral.

Another thing, somewhat unrelated; My speedometer is fluttering and totally unreliable. I hooked the end to a drill and the problem isn't the speedometer itself since it tracks the varying RPMs without issue, and doesn't flutter or anything. What do I call/where do I get the part that fits inside the wheel? I think that gear may be all chewed up and giving a false readout.

Thanks for all your help again, ride on!

For the neutral light, 2 more things to check. Look at the neutral switch itself.............put the bike in neutral and use your ohmmeter to confirm that the switch terminal is grounded. If the switch is good, move on to the light blue wire. Again use you ohmmeter to measure resistance (looking for 0 resistance) from the blue wire at the switch to the other end of the blue wire up at the neutral light. If that's all good then check for battery voltage at the other side of the neutral light bulb.

Speedo problems. Take a very careful look at the squared end of the inner cable down at the front wheel end. If the cable has never been lubed in 30 years, that squared end can become rounded, which could cause that fluttering. If you find the end rounded then its time for a new speedo cable.

The speedo drive gears need to be taken apart, cleaned and re-greased occasionally..............i.e. once every 8 to 10 years or so.
 
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