Turn signal won't cancel

[frodef]

I'm replacing the right-hand handlebar switches for a "new" unit (including master cylinder and the whole thing). When I first installed it, the kill-switch didn't make proper contact, so I disassembled the switch and cleaned up the rotating kill-switch (and starter button). After reassembly, the starter and kill-switch seems to work fine, and the turn indicator works, but the turn cancel button doesn't seem to do anything. The button makes and breaks contact as far as I can tell with my multimeter. I don't really know if it worked before I disassembled the switch, as I only really tested the starter/kill-switch.

Any tips on how the turn-signal relay works especially wrt. the cancel button, or otherwise how to figure out this problem?

Thanks!

[daveson]

When you plug the right handlebar switches back in, you have to also plug the brown/yellow wires together. For some reason the turn cancel switch wire has its own plug running alongside the handlebar switches plug.

[frodef]

Right, seems it was a poor connection in that (weirdly separate) connector. (Or truth be told I could have forgotten to plug it when testing before, though I thought I checked that..  )

Thanks!

[The Mighty Gryphon]

The turn signal relay has a lot of circuitry in it that isn't very well documented, especially with respect to the logic that is used to control the turn signals and the emergency flashers. 

The problems I've had were caused by failures in the integrated circuits.  I really wasn't able to troubleshoot to identify the bad part, I just replaced the IC's and hoped for the best.

My advice is to get another turn signal relay and do a swap, a working used one is okay.  If it fixes the problem, great, if not, you have eliminated the relay as the cause of the problem and gotten a spare.

[beemuker]

I had all kinds of weird issues with my turn signals on my sold K75 that went away when I replaced the turn signal relay with a used one i got off ebay. I still have the old one if somebody wants it, you can have it for postage.

[rbm]

When you plug the right handlebar switches back in, you have to also plug the brown/yellow wires together. For some reason the turn cancel switch wire has its own plug running alongside the handlebar switches plug.

There's a very good reason for that.  The right hand switches are connected to the harness with a 9-pin AMP connector.  Same goes for the left hand switches.  However for the right hand side, there are 10 wires to connect.  So instead of having to stock a different type of connector (possibly being a 12-position plug) at more expense and more likelihood of a supply chain problem, BMW chose to stick to a 9-position connector and handle the tenth wire with a single connector.

As for the relays with gremlins, sometimes the gremlins are related to poor and cracked solder joints, especially to the relay spade connectors.  Inspect the solder joints with a magnifier and look for ones that appear crusty and dull.  Reheating the suspect solder joints will reflow the existing solder and clear up these types of problems.