Consequences of Electrical Failure 'at speed'...

[jharvey]

Greetings all,

I recently had a fuse blow while I was pulling away from a stop sign. The fuse has been replaced and the electrical system checked, but with 35-year old electrical systems, who can really say? - and it raised the question in my mind, what happens if ?the lights go out? while the bike is underway?

If I'm riding down the road and suddenly there's no power to the spark plugs, will be spinning of the rear wheel keep the pistons moving, perhaps giving me an experience like aggressive downshifting until I can pull in the clutch and pull over to the side of the road, or will the rear wheel immediately lock up, with all the consequences and complications that come along with that? Has anyone here actually experienced this first hand?

Thanks

[JTGS850GL]

It will act just like you took your hand off the throttle. Nothing will lock up. You just need to get to a safe spot as soon as you can. Depending on which fuse blows you might loose your turn signals and headlight as well.

It has happened to me but usually with the glass fuses. Sometimes the fuses just fail from repeated vibration and heat cycles. Might also be something that's shorting in the harness so take a good look and check everything out. Especially in areas of connectors and where the harness is secured

Which fuse blew in your case?

[jharvey]

Thanks for the quick (and reassuring) response,

The fuse in question sits under the left-hand side panel, with the R/R, Ignition Control Unit, etc. Originally, it was a glass fuse, but some 20 years ago, someone went under that left side panel to cut away all those electrical components (I later learned that the GS400 had a reputation for bad Regulators, and while mine never gave me any trouble, presumably someone was replacing theirs that did.)

It was eventually repaired with a less expensive and presumably more robust R/R unit from a Honda, along with a newer plug type fuse (colored transparent top visible when plugged in), and it had served reliably ever since. However, about a year ago, the shop that did that work went out of business, and last winter when some other work was being done at a different location, if not the type of fuse, at least the housing was changed (two black rubber housings plugged into each other), and I remember at the time when the bike wouldn't start at the shop, we found that the new fuse hadn't been properly seated (and had gotten hot enough to partially melt the rubber). Reseating seemed to fix the problem, but when the fuse failed a few weeks ago, and both sides of that connection had so completely 'fused' that it came apart more like an O'Henry bar broken in the middle than a plug and socket (so it wasn't merely a case of me popping in a new fuse and riding away), I wonder if it was never COMPLETELY seated properly and just slowly overheated itself into failure over the last eight or ten months.

The replacement assembly now has the colored plastic top of the fuse visible again, plugged into a hard plastic housing. I also had them put together a full spare replacement assembly, including wires to the nearest connection points, that I'm keeping in my tail cone in case it happens again that I can't change a fuse because it's fused.

[60ratrod]

what probably happened is it more than likely corroded inside or not rated high enough amp wise, causing it to heat up and not blow the fuse until it did. those inline fuse holders tend to get hot and melt like that. If I have to use one of those, I go for a higher amp model than what I actually need, to help avoid this

[tkent02]

Maintenance is a beautiful thing.

[Big Rich]

Harvey - if you experience any sudden power loss, it depends on what gear you're in and how fast you're going at the time. Going down the highway in top gear and your main fuse blows, and your bike will just will just chug down but keep rolling. In first gear pulling from a stop sign, it can lock up the wheel pretty quick.

Either case, pull in the clutch and you'll be fine.

[Steve]

If you would like to experience it under controlled circumstances and maybe practice, just casually reach up with your right thumb (while keeping the throttle on) and turn the 'kill' switch OFF. Might even try that in different gears to see the difference.

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[jharvey]

Thanks for the insight. Being stuck on the side of the road with no power is one thing, but the thought of having the rear wheel lock up at speed would have 'adversely affected' my future riding enjoyment.

And I'll have to find an empty parking lot and try the Kill Switch advice. Always nice to know exactly what to expect.

Thanks again,

[Steve]

In any of the upper gears, you will not experience "lockup" unless you are on questionable surfaces. Even in the lower gears, I don't think you will lose traction, but in any event, a quick pull on the clutch lever will let you free-wheel to a stop, hopefully in a safe place.

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