Ghosts in my blinkers

[OldVet66]

The wires to the distance counter should be black/red and blue/red if I am reading my wiring diagram correctly.

[rustybronco]

Roger that; it may be time to open up the speedo...

Test it first! if you do need to get inside the speedo, let me be the first one to tell you, it won't give up it's innards 'quite' so easily.

I've got an idea floating around in my head for building a replacement TSCU out of a 'few' bits.
someone else, (who shall for the time being remain nameless) might have some information on building a replacement as well.

[bluewool]

Question: Why would the reed switch for the distance counter only affect the left signal? are there two reed switches? Does anyone have a sequence of operation for the signal control unit?

[sedelen]

I share pretty much the same problem, left turn signal not working while riding, on pretty much the same bike, '79 GS1000E, in the same general area, Central Florida. I haven't swapped the bulbs, but I will and will check for dirty high resistance grounds, haven't done that yet, and that seems plausable, but I have swapped out the speedometer and nothing has changed. I will have to check those grounds and swap those bulbs and see what happens. But you know, you just got to ask yourself this question, "Why would it do it when I'm riding and not idling or sitting still in the garage?" and "Why would a dirty ground or defective bulb not affect it
until I'm riding?" I think it's the TSCU, and I think it's sensitive to vibration,
so much so, it affects it's operation, higher rpm's, moving over the road, etc. But these peculiar problems usually make sense when the problem is found.

[OldVet66]

There may be an easy solution. The reed switch appears to be a single pole switch of sorts that is magnetically opened or closed. Looking at the wiring diagram the black/red and blue/red wire that goes to the speedometer connects to each end of the reed switch. The connectors are in the headlight bucket. Either just disconnecting them will make the turn signals manual, canceled with the manual canceling down switch or shorting them will. I suspect the switch is normally opened and cancels when the reed switch closes. I also might be entirely wrong, but I will put it to the test soon. I need to trace the down switch circuit, that should give me a better idea of what is going on.

[OldVet66]

It appears that I was right. With the wires to the reed switch disconnected, the turn signals still work manually and cancel with the manual canceling down switch. With the bad reed switch in the circuit my left turn signal screwed up and then both after a while. They would work intermittently at times. I suspect the reed switch loses it's tension and partially closes enough to confuse the turn signal module into constantly and erratically canceling. As soon as I changed speedometers, the turn signals started working. There is a magnet in the speedometer that spins near two plates that are connected to the reed switch. The circular magnet has regularly spaced cut outs in it so that it only affects the switch when the high spots span the plates as it rotates with the speedometer. Pull the Black/red and blue/red wire in the headlight housing, and if the reed switch is the problem, you will have working manual canceling turn signals.

[rustybronco]

Oldvet66, a reed switch is magnetically operated. it has no normally open or closed position. when you rotate the speedometer cable the contacts close, open, close, open ect. the reed switch will either be open or closed, depending on where the speedometer input 'shaft' has stopped and will stay that way until the shaft is rotated further.

a reed switch is not a normally open or closed switch who's contacts are mechanically operated.

[OldVet66]

Bottom line, the turn signals work normally without the reed switch. I don't pretend to know how their failure affects the circuit, but I know it does. They are rated for about a million cycles. I haven't ridden the bike for any time with the switch out of the circuit, but I suspect that it is part of a relay and timing circuit in the control module. Without the reed switch in the circuit I also suspect it will continue to work until manually canceled. But of coarse, I could be wrong, only a long term test will prove it one way or the other. http://en.wikipedia.org/wiki/Reed_switch

[rustybronco]

Oldvet66, I was 'composting' my response during your last post and didn't see the outcome of your test until after you had completed it..

I don't claim to know all about the way the system works either. the only thing that makes sense is something on the TSCU board doesn't like the reed switch in circuit as you suspect. quite possibly a leaky cap or some other device on board. either way a board member has already worked up a replacement TSCU based on a MPS430. hopefully some time in the near future replacement units will be assembled and ready for those who need them.

[OldVet66]

Way cool. It is a simple setup in the speedometer. It looks like they may have used a high content silver solder to solder the reed switch to the plates but to tell you the truth, even though mine works, I think I would be happier with it out of the circuit and working manually. I dissected my old speedometer. I hope the new units don't rely on a distance counter. The blinkers blink roughly ten times before self cancel, so a timer circuit of some type could work just as well.

[cliffnote]

Process of Elimination

I have checked grounds, swapped bulbs, cleaned the switch and even removed the wires to the speed sensor. None of these actions fixed the problem of intermittent left turn signal. I figure it shouldn't be the flasher since it seems the blinkers wouldn't work on the right if that were the cause. In my estimation, this leaves the expensive TSCU. I welcome any other possible remedies or a good deal on a TSCU if someone has one.

[whiterabbitt]

spend the $2.00 on a heavy duty automotive flasher and try it, then if that dont work look at something else.

[chuck hahn]

From the 1000 E service manual supplementals..http://www.mtsac.edu/%7Ecliff/storage/gs/GS1000.pdf Scroll down to the E supplimentals and select self cancelling turn signals.

[Furious D]

spend the $2.00 on a heavy duty automotive flasher and try it, then if that dont work look at something else.

That fixed my problem . I could not get the right turn signal to work . Being an electrician I tried to over-analyze the problem . I borrowed the flasher out of my old truck and it works great. Only thing I have to figure out is why the factory flasher is 3 prong but the 2 prong one works perfect. I seem to remember that the extra terminal on a 3 prong is ground but I'm not positive thats the case.

[whiterabbitt]

check down at the auto parts store, they may have one that is a match to your old one. It might cost a bit more but, how much is your peace of mind worth?