The Flasher module on a recently acquired '88 K100RS SE has a problem with the right turn signals.

Operation of the left turn signals is correct, the left handlebar switch turns them on and the cancel switch on the right cancels them.

The hazard flasher switch works normally as well.

The problem is that the right handlebar switch turns on both right and left turn signals, and the cancel switch cancels them.

I have replaced the module with one from another bike and the signals all work properly.  When I take the faulty module to another bike the same problem happens on that bike.

As far as I can troubleshoot, the relays and the relay drivers are working properly, beyond that, I can't seem to figure out what is going on because of those 10 pin strips on the circuit board.  I have purcased a replacement, but at the price of these things, I would really like to fix it and put it in my spares stash.

Anybody seen this problem and fixed it?

That problem is the same as when fuse #7 is open circuit so it may be the tracks on the board that carry that power that are broken or dry solder.

RickG,Thanks, I just looked at the circuits connected to pin #15 and the solder joints are good with the traces having conductivity and all the diodes working properly.  I guess it's back to the drawing board.

Try multimeter comparison readings between the good one and the bad one.
Happy New Year regards Martin.

Does anything look overheated?  Maybe post photos.

Nothing is burnt or out of the ordinary.  All solder joints are good. 

I have spent at least an hour looking at the board through a 10x magnifier and haven't seen anything that could be causing a problem.

I have tested the function of all the diodes on the board and as far as I can tell they are all okay.

Because of those 3 white 10 pin terminal strips on the board I can't really trace the circuitry to see where things go.  Makes it hard to figure out what the circuit is doing.

I am getting some bizarre resistance readings around the 4093 IC(every pin has some continuity to every other pin).  Since it's a CMOS device and static sensitive and cheap to replace, I have ordered a replacement and should have it next week.  Until then, I am hoping that RBM will chime in with a suggestion or two.

Because of the CMOS stuff on the board, I'm hesitant about poking around in a good module.

I have a spare flasher with a broken relay contact, I just got the same results for that IC

Only two of the readings were constant, the others were momentary.

if measuring anything cmos
make sure that the ground pin = common  is connected to an earth some where , then whatever will be safe

if the ic has a "b" after it, (suffix ) IT IS A BUFFERED VERSION AND IS QUITE RESILIENT .. often found with suffixes "b p "

good luck

Good to know, it does have BP at the end,  at least mine does.

Yes, it's buffered.  And the replacement is buffered as well.

I am suspecting that something internal to the IC is triggering both multivibrators when the right side is activated.  At least I hope so.  All the diodes surrounding the IC look to be okay, at least without pulling them all to test them away from the board.  I have to admit that my component level troubleshooting leaves a lot to be desired.

Maybe something is supposed to cancel the left, but not working, just guessing.

Probably right about that, but the schematic is almost useless for figuring out what is going on.  Those 10 pin arrays make it impossible for me to trace the circuits.  It's supposed to be a couple of astable multivibrators, one for each side, but the circuits as shown don't make sense to me.

Brilliant!
don't see a IC Component Socket

You de-soldered old and re-soldered new one in?

Doesn't the auto cancel just disengage turn signal after whatever the length of time? Or does moto need to be in motion?

You have to unsolder the IC.  You don't want to use sockets in vehicle applications because the chips can vibrate out.  Unsoldering is a fussy job that requires a low wattage soldering iron, and a solder sucker to pull the melted solder out of the joint.  Too much heat or holding it too long and you can burn the trace off the circuit board.  Since the module doesn't work anyway, it's worth a try.

Signal cancellation is after the bike travels a distance of something like 600 meters which is measured by a circuit somewhere that gets a signal from the speedometer.  Since I don't see anything in the flasher that looks like a counter, I am guessing the count is done in the instrument cluster and a cancelling pulse is sent to the flasher.  I'm probably wrong, but it sounds good.

Per the owner manual it's about 210 meters to auto-cancel.

I could be just as wrong as you but I also think that the instrument cluster does the "math" and sends a kill signal to the flasher relay. (via the blue/green wire to flasher relay - probably a ground signal)

Good one.

How many watts the solder,  and how many max seconds maybe 3?

On my older bike cancelling is after say 10 seconds at speed, at low speeds about 200 meters, cause you don't want it to cancel if your stationary at a busy intersection, or traffic lights.

daveyson wrote:Good one.

How many watts the solder,  and how many max seconds maybe 3?

On my older bike cancelling is after say 10 seconds at speed, at low speeds about 200 meters, cause you don't want it to cancel if your stationary at a busy intersection, or traffic lights.

I use a 30Watt soldering pencil.  You have to watch the joint to spot when the solder goes liquid and then get the nozzle of the bulb on it and let the bulb suck the solder out.  Takes a little practice to get the moves down.

https://www.ebay.com/itm/BRAND-NEW-30-WATT-ELECTRIC-PENCIL-SOLDERING-IRON-FREE-SHIPPING/132997855627?hash=item1ef74a398b:g:c3EAAOSwbYZXZCSmUSPSFirstClass!14052!US!-1

https://www.ebay.com/itm/Desoldering-Bulb-for-Soldering-Irons-Solder-Removal-Tool/123253998185?epid=1312037125&hash=item1cb282c269:g:vNkAAOSwYUdbTNCo

There is no timer on the cancel, it's all based on distance.  As Duck mentioned about 200 meters.  I think that is where I came up with the 600 number I put down.  200 meters is 656 feet.

you sold me I'll take 2 
Thank you