Turn Signal Control Unit

[dwvoss]

I've been searching the old posts related to Turn Signal problems and have seen many references to the infamous Turn Signal Control Unit. It appears that there are at least 2 different versions of this unit. One that can be disconnected leaving the turn signals working without the auto cancel feature, and an ?older? version that has to be in-line for the turn signals to function at all. Is this correct?

The service manual I've acquired is for the 850G and not the 850L, so isn't exactly accurate for my bike. Does the attached picture show the infamous TSCU? Aside from losing the auto-cancel function, are there any negative side effects from disconnecting this unit?

[renobruce]

I like the self-cancelling feature. It works great on the 1150, but the one on my 1000 failed. I was not about to spend $300 on a new one, so I converted it to manual. I get caught sometimes rolling down the road with my turn signal on.

[DanTheMan]

Mine is supposed to have the auto cancel feature, but it's only worked for right turns since I bought the bike. Now, even the right turn cancel feature is dying. Not worth the cost to replace until the whole switch dies....O

[GregM.]

I like the feature too, but it only works some of the time. In fact, not that much at all, anymore. I used to try and figure out when it working - why? Just starting off on a ride or later in a ride... morning time or afternoon... high humidity or dry... left turn or right... high rpm or low? I had various theorys, but could never really duplicate them consistently.

Didn't know how to vote in the poll... I wish it worked all the time, I don't see any disadvantage to the feature. But is buying a new one the only way to fix it? Are they really $300? Heck no, I'm not going to carry a spare one, I just use 'em manually.

So if this a common problem, you experienced guys must know what the problem is... How could I get mine to work all the time? Or is the only way to get a new one?

Any guarantee a new one will work permanently? Is it better than the original?What causes these things to become intermittent?

[Ghostgs1]

Yes, the new one will cost $300 and no, it won't last. Best fix is to convert to a manual switch and make the few wiring changes to make it work. I still overlook cancelling the switch now and then, but it is still better than a new control box. Ray

[Grandpa]

I like this feature on my GK and on my previous 850's. Last year my speedometer cable broke during a ride. My riding buddies kept calling me on the CB to tell me to cancel my turn signals. It only works in conjunction with a working speedometer.

[denydog]

I hear that. I had my speedometer cable break last week. I must have ridden at least twenty miles with the signal flashing since then. I'm used to the self canceling feature and look forward to having it working when I get the new speedo cable!

[8trackmind]

Self canceling turn signals! #-o
You guys are bunch of weenies!

[Boondocks]

I like the feature too, but it only works some of the time. In fact, not that much at all, anymore. I used to try and figure out when it working - why? Just starting off on a ride or later in a ride... morning time or afternoon... high humidity or dry... left turn or right... high rpm or low? I had various theorys, but could never really duplicate them consistently.

Didn't know how to vote in the poll... I wish it worked all the time, I don't see any disadvantage to the feature. But is buying a new one the only way to fix it? Are they really $300? Heck no, I'm not going to carry a spare one, I just use 'em manually.

So if this a common problem, you experienced guys must know what the problem is... How could I get mine to work all the time? Or is the only way to get a new one?

Any guarantee a new one will work permanently? Is it better than the original?What causes these things to become intermittent?

The "infamous turn signal control unit" is a bad rap. The TCU gets blamed every time when no troubleshooting is done or the function isn't understood. The TCU is electronic and has no moving parts. The part that typically malfunctions but escapes blame is the turn signal switch itself. Most people don't seem to recognize that this is not a 3-position switch, but a 5-position switch. When the turn signal switch sticks in the wrong position, as they often do, the signal won't turn off and the TCU gets wrongly blamed.

For an explanation of what is probably happening with your intermittent turn signal problem, see my post at Self Cancelling Turn Signals Function.

[Grandpa]

Self canceling turn signals! #-o
You guys are bunch of weenies!

...and proud of it!

Weenie Gramps

[8trackmind]

...and proud of it!

Weenie Gramps

Good to see someone around here can still take a joke. Good on ya ,Gramps

[49er]

I think Boondocks is on the money here. I have a reliable one on my 850.
Many accidents/deaths are caused through riders forgetting to cancel out their manual indicators.
Cheers
Ian G

[GregM.]

Amazing help!! You guys are the best. Now another fun little project to fiddle with. Thanks a ton.

[Jethro]

Neither of my GS's had a self cancelling system when I got them, they had already been modded out, so I rarely forget as I have been "myself" cancelling for 15 years. A nice mod would be a late model "push to cancel" bar switch. That would avoid me pushing the signal past the middle every so often.