1979 GS850 turn signal system, how is is supposed to properly work?

[onchiman]

I'm bit by bit restoring a '79 GS850. The turn signals blink okay but only if I hold the switch right or left. The switch seems spring loaded to return to the middle "off" position. I find it somewhat inconvienient at times to hold in the clutch while in traffic and also hold the thumb the switch right or left to display turn signals. My question is, how is this setup supposed to work? I believe that once the switch is pushed right or left, the timer/auto cancel unit takes over from there? If that's the case does this mean the unit is shot or has it perhaps been bypassed by a po?

[Boondocks]

I described how it works at Self-Cancelling Turn Signals. When the turn signal switch is moved to the side, it triggers the sensor and is spring loaded to move slightly back but still well off the center position which would turn it off. If your turn signals are supposed to be self-cancelling but are spring loaded to return to center and won't work unless pressure is applied, it sounds like a PO may have modified it.

[onchiman]

Great info! I'll start with the switch and work through the circuit there. Mechanically my switch may be the culprit because it always returns to the center "off" position. From your description the switch is supposed to return slightly towards the center but not all the way. Interestingly, the switch while in the center position can also be pressed "downward" is that also an "off"? Seems redundant if everything is off in the center position anyway!

[Steve]

Boondocks,

Thanks for the info, especially the detailed information in the link. My signals have worked beautifully, but I was wondering why the switch did not return to the center. Now I know that is normal.



Onchiman,

Pushing the turn signal button up or down is your headlight high beam/low beam selector.


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[mark]

Normally its the "black box" that fails, and since they cost over $300 to replace most people do what it sounds like your PO did, eliminate the black box, put in some cheap flashers, and let it go. They never worked well anyway.

The standard modification is to go to a manual turn signal switch from another model and used automotive flashers.

The self cancelling system was notoriously bad, the general concensus is not to mess with it (but its your bike of course). In short, I think the correct way that the self-cancelling unit works is to find itself in the trash.

[renobruce]

It sounds like your black box is toast, or has been removed. You need to get a manual switch. When you flip the manual switch, it stays to the left or right on the switch's contact point until you move the switch back to center. Any manual switch from 77-80 should work.

[scotto58]

Onchiman,

Pushing the turn signal button up or down is your headlight high beam/low beam selector.


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Steve,

Not on a 79 GS850. There's a seperate hi/low switch.

[Steve]

OK, I did not know that. Just for my information, when did they combine the switches? And, on what bikes? My previous '81 450 and my current '82 650 have separate switches, so I was assuming that it was a feature on the larger bikes, and really have no idea when it was introduced.

Thanks for the correction.


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[romtang]

FYI -

On my 80 GS850G the turn signals and high/low beam are all in one.=P~

[dcollins]

I had the exact same problem on my 79 GS850G. It was the black box. The suggestion to trash the black box is the best.

You do have to replace the switch assembly on the handlebars, I found one at a local salvage off of another GS. You'll have to find one that has the hi/lo switch and the on/off switch as well as the 3-position left/right switch that stays over when you move it. Otherwise you probably won't have any power to your headlights without re-wiring the switch.

Jumpering around the black box isn't too hard, It's been a while since I did it, but if I recall, you can jumper the power coming from the left/right switch back to the respective light circuits on the same connector.

I put the automotive flasher on the hot wire going to the turn signal switch.

There's a slight timelag between moving the switch and the lights coming on, but you don't have to sit at a stoplight trying to hold the clutch and flick the switch at the same time.

[49er]

My 79 GS850 has seperate switches for turn indicator and low/high beam.
The indicator switch still works well. It self cancels after around 5 seconds or can be manually cancelled by sliding the knob downward.

[onchiman]

Thanks for all the info. At this point I think I'll go with the conversion to manual. Never had a self-cancelling turn signal on a bike before therefor I won't miss it. I tried to have a lookie at the mysterious "black box". Seems there's only a couple of coil type relays visible. The real guts of the thing seem permanently encased in epoxy. Maybe someday I dissect it just to see what form of evil is inside. I wonder if Suzuki perhaps contracted this part out to Lucas?