Blows ignition fuse when put into gear

[davidsymons53]

I am back to working on the wiring on the bike. I know the wiring for the starter button is not working. I can jump the solenoid and get the bike started. With the engine running and the green neutral light on, I shift into first gear let out the clutch and the ignition fuse blows in the engine dies.

With the engine running and the green neutral light on, I can start shifting up through the gears and ignition fuse blows and the engine dies.

Do you think this is connected to the starter button not working, or is it a second wiring problem?

David

[DAVINCI]

You probably have multiple problems. I'd suspect bad grounds. Clean all your ground connections:

battery

battery to frame

frame to engine (at middle drive)

Wire harness to regulator

Proper clean involves removing the bolt, pulling the connector off, use emory or wire brush to scrape off all the old crud from the connection point, the bolt and the wire end, then re-install. Good -n - tight.

[crazy steve]

Do you think this is connected to the starter button not working, or is it a second wiring problem?

That's a second wiring problem. You probably have a bare spot in the wiring to your neutral switch; try removing the bulb for the neutral light. If the problem goes away, check the harness coming from your ignition pickups. I'd look specifically where it runs under the shifter cover and behind the motor on it's way to the plug behind the fusebox.

[DAVINCI]

I don't know where you're going with this, Steve, but:


A bare spot in the wire to the neutral switch would not cause the engine to die, if it were to short to ground, it would only simulate the action of the neutral switch and keep the bulb lit.

Along the same lines, though, IF there were a bare spot and there was water in the harness, that can cause the same symptom. When the neutral switch is made the light is lit, the second the switch goes open that current is looking for another path and the pickup wires may be it.

[crazy steve]

...Along the same lines, though, IF there were a bare spot and there was water in the harness, that can cause the same symptom. When the neutral switch is made the light is lit, the second the switch goes open that current is looking for another path and the pickup wires may be it.

That's what I suspect is going on. You wouldn't even need any water; the pickup coils have a high enough resistance that as long as the light is on via the switch you wouldn't get much 'leakage' into the circuit. But remove the ground path through the switch, then the current starts looking for another path. Unplugging the light will remove power at that point in the harness, so if that's the problem it should clear...

Of course, now you have to find where it is...

[davidsymons53]

Thanks for the replies. I have some new info. Last fall I torqued the oil drain bolt out of the oil pan. This spring I replace the oil pan and I had to reattach of the brackets that held the two sets of wires up out of the way. I am now wondering, if one of those sets of wires runs from the neutral switch.

Does this sound reasonable to you guys?

David

[natemoen]

Yeah, the loom on the left side has the neutral light wire in it.

[davidsymons53]

Thanks Nate. That's where I'll start.

David

[DGXSER]

Just to be clear, does the fuse blow and engine die as soon as you put it in gear? Or does it remain running until you let out the clutch?

If it dies as soon as you put it in gear, that would indicate something with the neutral switch. If it is only after you let out the clutch, then it is most likely in the clutch switch.

On the 81 models Yamaha implemented the true Neutral safety, meaning that not only does it light the light in the tach, but it actually keeps you from starting the bike if it is not in Neutral, unless you have the clutch pulled in. If you pull the clutch while in gear it will start.

So, somewhere in that circuit you have a wiring issue, or a short, the starting system is included in the ignition fuse.

[crazy steve]

On the 81 models Yamaha implemented the true Neutral safety, meaning that not only does it light the light in the tach, but it actually keeps you from starting the bike if it is not in Neutral, unless you have the clutch pulled in. If you pull the clutch while in gear it will start..

I thought it was only the '82-up bikes that had that.... there's no mention of it in the FSM or on the wiring diagrams.

To verify that the problem is in the neutral switch, you can pull the turn signal fuse (removing power from the neutral light) then try it.

[DGXSER]

I thought so to Steve, and in fact my first SH did NOT have that feature and it was in much better shape and more stock than this one was when I got it. But I put the stock wiring harness from ole Thunderstruck on this bike, and it still will not start unless I pull the clutch with it in gear. Even the fact there is a spot to connect a switch form the clutch tells me that this was a stock feature, what other reason is there for a clutch switch?

So I am left to think it was defeated on my first one some how, as it to had the switch, I just never thought about it.

[davidsymons53]

"Just to be clear, does the fuse blow and engine die as soon as you put it in gear? Or does it remain running until you let out the clutch?

If it dies as soon as you put it in gear, that would indicate something with the neutral switch."

The fuse blows and engine dies as soon as I let out the clutch while it is in gear.

The fuse blows and engine dies when I shift through the gears while holding the clutch lever.

[davidsymons53]

Back from holidays

I'm back from holidays in facing my wiring problems. To tell the truth, it scares the crap out of me to get into wiring problems. I don't mind working on mechanical problems as long as I have enough information to get the job done. But when it comes to wiring on a bike or car I feel overwhelmed, and worry I'll do more harm than good.

I've arranged to take the bike into a friend of mine to help me with this troubleshooting. Is there a way to easily and temporarily bypass the neutral switch? That way I'll know before I go that it is definitely in the neutral switch circuitry.

Sorry to be such a pain with this problem, but "I can do what I can do, and what I can't do I have to get help"!

Thanks in advance, David

[BA80]

An easier way to check if the wiring to the neutral light switch is just disconnect the wire from the switch. Just loosen the phillips screw on the switch and pull the wire out.

That's what it sounds like to me also. BTDT

A bad pickup coil wire can act the same way also.

[davidsymons53]

Will disconnecting that wire bypass the neutral switch, letting me uses the bike?

David