1979 GS425E neutral light and gear position issues

[Barneycanoe]

Hello, I could use some help.

My wife's 1979 GS425E stopped showing the neutral light and the gear positions on a ride on Saturday. She though they went away and came back briefly and then nada.

I have looked at the wiring and confirmed the bulbs are ok. These two sets of light(s) are connected by a common ground, and also by the gear position switch.

Everything else on the same ground path (horn, starter switch, etc.) works fine, so I don't believe it is the ground.

Couple of questions:

Does anyone have experience of this gear position switch failing, does it go suddenly or is it intermittent for a while before going - it looks all right to me, the little circles are scored where the plunger would make contact but that seems reasonable to me.

How does one test that switch? Presumably the plunger is connected to the ground of the bike as it is in the gearbox?

Appreciate the help of the experts

[tom203]

The little pin and spring that makes contact with those "little circles" is either dirty or worn down so you don't get consistent ground to light the bulbs.

[GS(X)400]

Had a similar issue. Remove the gear switch and replace the 0-ring that goes with it. Clean the surface of the gear switch with 00 steel wool and a contact cleaner and then clean the pin on the inside of the mechinism

[Steve]

I have looked at the wiring and confirmed the bulbs are ok. These two sets of light(s) are connected by a common ground, and also by the gear position switch.

Everything else on the same ground path (horn, starter switch, etc.) works fine, so I don't believe it is the ground.

Actually, the gear position lights have a common SOURCE, not a ground. One power wire feeds all the lights, then individual wires go down to the selector switch, where they are finally grounded (one at a time) to show the gear position.

Look for a connector near the back of the fuel tank that has all those wires. If they are all going out at once, it will either be at the source, at this connector or the selector switch at the bottom.

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[Guest]

I'd be doing a +1 on cleaning the switch and replacing the O ring, that's where they're all grounded alternately to light up and it seems to be a reasonably common issue after many years of use and/or neglect...

[Barneycanoe]

Hugely helpful. Thank you all.

Dave

But after thoroughly cleaning the switch and pawl I still have no lights.

Dave

[850GT_Rider]

Hugely helpful. Thank you all.

Dave

But after thoroughly cleaning the switch and pawl I still have no lights.

Dave

If you have the wiring diagram, you could independently ground each of the wires leading from the indicators. That would tell you if the problem was in the lights or the switch.

[Guest]

If you have the wiring diagram, you could independently ground each of the wires leading from the indicators. That would tell you if the problem was in the lights or the switch.

Yup, that would definitely tell you!

Not sure how different the 425 will be to the 450, but on the 450 there's a six way connector for the gear position grounds and a separate bullet connector for neutral.

[Barneycanoe]

Success! I should have been more thorough yesterday. The orange source wire that feeds the gear lights and the neutral bulb is Y-connected to the orange wire that goes down to the plastic connecter under the tank. After 34 years the wire had broken at the Y joint.

Thanks all, Steve especially for pointing out that the pieces had a common source!

Dave

[Guest]

Typical... Steve's right again!

Onya Steve

[Steve]

Typical... Steve's right again!

Onya Steve

Dang it, I gotta stop doing that.

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[Guest]

Dang it, I gotta stop doing that.

.

Nah... keep it up, I like it