Turn signal control unit

[Guest]

I got a 1979 GS850 from a friend last fall. Lots of things to fix. Lately i tried to get my turn signals to work properly in order to get it approved by the swedish DMV. It would flash, but once i release the switch it stops blinking. Very annoying and illegal over here. I read on this forum that the GS has this control unit. Expensive, hard to find and seldom works. According to a wiring diagram the unit was connected by one 4-pin and one 6-pin connector. I followed the harness and found out the whole unit was removed and replaced by a couple of jumpers. No wonder it didn't work as expected. More forum surfing lead me to someone who constructed a digital unit built up on a micro controller and a timer circuit but i couldn't figure out how to program such a thing so i made up a cheap workaround based on simple 12v relays. The auto-cancelling feature is gone but i can live without it. This is how it works:Each side (L and R) requires 2 relays: one for the "hold circuit" and one to actually let flash signal thru. Then the blinkers wont stop, so we need one more relay for the cancel function. This sums up to 5 relays where the first four are simplest on-off and the cancel-relay has to be a switch because it will feed the others with 12v when its not active and break the circuit when hitting the cancel switch. Therefore the cancel relay must have the 87a pin. So pushing the momentary switch on the handlebar to the left will cause a pulse that makes the first relay to switch on and then feed its own coil in a hold function. At the same time the second relay will switch on and lead the flash signal to left-hand lamps and indicators. The fifth relay has a constant +12V on its control coil, and also on pin 30. Cancel switch is basically a momentary ground wire that completes the control circuit causing the relay to switch and stop feeding 12V into the first two relays. I just bought cheap generic 12v relays, taped them together, soldered the connectors and some jumpers and it works perfect on my GS.

[Stalin]

I Apologize for my poorly drawn diagram. First time using an on-line editor. Hard to find the right symbols.

[Nessism]

Nice work and thanks for posting!

[azr]

Very interesting, and yest thanks for posting.

[posplayr]

Are we talking about an alternative to this (sans Auto cancel)?

http://www.thegsresources.com/_forum/showthread.php?221819-1st-generation-AUTO-cancel-TSCU-quot-banging-the-bits-quot&highlight=TSCU

[Stalin]

Yes. Thats the one.

[Tanerrc]

So I'm not the best at reading the schematic diagrams. Do you have anymore pictures and information about this whole thing?
Do all the relays have to be 5 pronged? Seems like 4 of them only need 4 prongs.
Also, other than being 12v does the relay need to be any specific kind? Looks like some are $30 a pop which isn't very cheap when you buy 5 of them.
What does the rectangle box with a line curling around it in the diagram mean?

[rustybronco]

Do all the relays have to be 5 pronged? Seems like 4 of them only need 4 prongs.

All of them can be four pronged. The cancel would need to be a Normally Closed relay

Also, other than being 12v does the relay need to be any specific kind?

Just something durable.

What does the rectangle box with a line curling around it in the diagram mean?

That is the solenoid portion of the relay.

You can also do the same thing with just three relays.

https://www.thegsresources.com/_forum/attachment.php?attachmentid=15195&d=1323780825

[Tanerrc]

Awesome. Thanks!

So with this three relay system I need two 6 pronged relays and one 4 pronged relay, correct?
I understand 75% of this diagram so I'm going to go ahead and buy the materials and get started.
I'm probably going to have a few more questions though.

[rustybronco]

Yes, but the 4 pronged relays are easier to obtain. In fact I have a pile of them.

[Stalin]

Yes Rustybronco (and Tanerrc) I used these relays because they were cheap and easy to get. Less than 5 dollars each in our PepBoys-type-store. And i already had a couple of them at home.
So you need 4 relays with 4 terminals (normally open) OR 2 of the more sophiticated shown in the other thread.
In addition, for the cancel function you need 1 normally closed OR as in my example switching relay. Hence the 5 terminals as it will switch between two of the output terminals, and you still only need do connect 4.
Good luck, Tannerc! questions are welcome

[Tanerrc]

So I followed the wiring diagram the best I could but this thing isn't working right. It'll turn on my left turn signal and it will stay on (not blinking) until I hit the manual cancel switch. The right signal will turn on and stay on (not blinking) but won't turn off when I hit the manual cancel switch.

Can anyone help me out? Not really sure where to go from here.

I'm assuming something is wrong with the cancel relay so I put a picture of it up here.

[mikerophone]

This is great - I have 3) 850's right now and 2 of them have iffy TSCU's, the cheapest one I've found was $50 on eBay and it was gone the next day.

I might have have missed it but does this retain the self canceling feature?

[posplayr]

This is great - I have 3) 850's right now and 2 of them have iffy TSCU's, the cheapest one I've found was $50 on eBay and it was gone the next day.

I might have have missed it but does this retain the self canceling feature?

From Stalin (OP)

The auto-cancelling feature is gone but i can live without it.

[bodin62]

Hi I am new to this forum and I was looking at the drawing and can not figure it out. I looked at the picture of the 5 relays wired, but do you have a diagram with colors of wires that corresponds
to the picture. On the diagram where wires cross and there is a dot does this mean that the wires are soldered together?