Self cancel signal module replacement 1979 GS

[Normk]

We have discussed some alternatives for the OEM Suzuki self canceling signal light module and I committed to posting a solution but have been procrastinating.

There's no excuse for this as it is a simple as pie circuit but had to make the time to mock-up and test. Apologies if someone was inconvenienced...

I will post a diagram in a subsequent post but prefer to follow my usual practice of attempting to outline the problem, as I see it, and to describe the solution. IME, many people are concerned about electrical systems because they simply have not had the opportunity to acquire sufficient experience and theory to be comfortable with systems which are usually much less complicated than those with which they normally deal in the course of their career.

Here's a brief description of the operation of the stock system:

The bar switch has two functions: direction selection and cancellation. The direction switch section has three positions Left on; Open/Off; Right on. The cancel switch section has two positions Off/open; On/cancel.

There is a power wire from switched fuse box to the signal switch which is shared by the two, direction & cancel switches.

In order to select right signal, the switch is pushed to the right which makes contact between the switched power to the right signal wire leading to the signal light module. This power "tells" the signal light module to turn the right signals on and the signals remain on, flashing until something intervenes. Ditto the left signals.

In order to cancel (stop or turn off) the signals to one side, switched power can be shut off but turning off the ignition switch, removing the fuse or unplugging wiring. When reconnected, the signals have reverted to off.

The rider is able to cancel signal operation by one of two manual modes: cancel switch, by pressing the signal switch lever downward; or, by selecting the opposite direction turn signals. In the event of operating the cancel switch, to apply shared power from the switch to the cancel wire leading to the signal light module which "tells" the module to cancel/shut off the signal lights.

In the event that the signal lights are operating in one direction, pushing the signal switch to activate the opposite direction "tells" the module to cancel the side not selected and to operate the selected side.

The automatic mode of cancellation makes use of a small inductive winding or coil of wire in the speedometer head, which is connected to the signal light module. A magnet, afixed to the speedometer drive, induces/generates an AC voltage in the winding/coil when the bike is in motion. The module notes the presence oscillations in the winding circuit as an indication that the bike is in motion and runs its timer until the stored time has elapsed, after which it turns off the signals.

More in the next post.

[Normk]

Here is a simple diagram of a typical Bosch type relay:

Oh, yes..this site doesn't embed the photo so it is attached. Not a problem.

Note the five numbered leads for this type of relay. The standard identification numbers for the relay's magnetic winding are numbers 85 & 86. These are simply the ends of a coil of wire sized to operate with a very small current (low amps) at around 12 volts.

When one applies power across (connects to power) number 85 & 86, a current flow creates a magnetic field in the winding which attracts the moveable switch arm in the relay. This simply turns on the relay in the same way as flipping a switch.

If we connect #85 to the right side switch contact (Green/black wire on my diagram leading to the module) and ground (connect to the frame or other negative for the bike), operating the right side signal switch will cause the relay to operate/click. We can do the same for the left, and the signal lights will illuminate when they are connected to the relay's contacts but more on that.

Note that there are three other leads indicated by 30, 87 & 87a.

It will be seen from the diagram that there is a line between 30 and 87a which is meant to indicate the switch contacts within the relay. The relay has two switched contacts 87 & 87a, plus one common 30 which is either connected to 87 or 87a, depending on the relay. Note also that I had to scratch out the incorrect labelling which is why the dot next to 87 because I had incorrectly labelled it "87a", sorry.

In the position shown, the contact arm is connecting 30 to 87a. This is the normal position for the relay when power is not connected to 85 & 86, the magnetic winding. When power is applied to 85 & 86, the relay's contact arm moves to disconnect 30 from 87a and connect it to 87. 87 is, therefore, a normally open contact while 87a is a normally closed one.

The role of normally open or normally closed is critical to understanding the operation of switches and relays, but as can be seen, is not rocket science. A typical horn or starter button is normally open and so closed (turned on) by the rider in order to power the horn or starter relay.

More next post.

[Normk]

Attached is a more complete circuit which I will describe:

Notice that 85 is grounded (connected to chassis negative) and that 86 is connected to one side of a push button switch? These two can be reversed with no difference in operation. As shown there is a connection between 30 and 87a (normally closed contacts) so there is power in the circuit between battery positive, fuse, 30, 87a Bulb "a", chassis ground, and battery negative.

Yes, I know that current flows from negative to positive but motor vehicle power systems are always described using the "Conventional Theory" as this makes description and testing concepts easier to describe.

In this mode of the relay's operation, the light Bulb "a" is on and remains on until the fuse is removed or unless the relay is operated. When the push button is operated, current flows in the circuit Battery +, fuse, Push button, 86, relay magnetic winding, 85, ground, battery negative. The resulting magnetic field pulls the relay's contact arm from 87a to 87, opening this circuit so the Bulb "a" is turned off.

30 to 87a has been opened but 30 to 87 has been closed so the current flow will now be established: Battery +, fuse, 30, 87 Bulb "B" ground, so Bulb "B" illuminates. If we powered something such as the starter relay from 87 also, we would have a starter circuit with one light telling us that the starter was not operating and the other Bulb"B" telling when it was. No reason to do this but simply an illustration.

It can be seen from the above that we can use a relay to close a circuit (allow current flow) or to open it (stop current flow). Both modes are very useful and both will be used in the signal module replacement circuit.

More next post. Hope this is useful to someone as felt it might be better to begin at a more basic level and build a bit rather than simply posting the diagram which comes next two posts. Running out of energy though....

[Normk]

Next is the cancel relay section of the module replacement:

In this section a standard Bosch relay is subsituted for part of the signal module's function in order to allow the original cancel switch to function.

The relay is connected without the 87 (normally open) circuit being used which is the reverse of most relay operations. In fact, many/most of the Bosch relays on the market do not have the 87a circuit so one must take care to select one for this application.

Note that 86 is connected to ground while 85 to the Orange/yellow (test this function with meter or test light at the module plug after removing the module. As connected, the relay operates/clicks when the key is on and the cancel switch is operated. This will open/shut off the circuit powering the signals in order to stop signal operation.

Hmm, better show a latched relay....OK next post, then the main diagram.

Note that 30 is connected to the fuse box circuit. I used a new, direct wire to by-pass the harness and forgot to note the fuse box circuit wire color but easy to find with meter or test lead if wishing to use the existing wire to the module as the power for the new signal circuit.

When key is on the circuit Fusebox signal fuse to 30 to 87a is closed and supplies power to the signal light relays for right and left by means of the wire leading off the page to the right.

[Normk]

Sorry about the mess but simply modified the previous diagram:

Note that the circuit: Battery +, Fuse, 30, 87, Bulb "B", ground is complete so bulb is on. Note also that there is a new circuit in parallel with the bulb so it is also in operation: Battery +, Fuse, 30, 87, 86, winding, 85, ground. This means that current is flowing through the magnetic winding of the relay, holding the switch contacts between 30 and 87. In this mode the relay remains switched on through this circuit and since it is holding itself, it is said to be "latched". The relay will remain latched until power is disconnected from the winding circuit in some manner, usually by disconnecting 30.

So how does it get into this mode? Having the circuit 87 to 86 (or could be to 85 if 86 is grounded) connected means that operating the push button closes the circuit Battery + to 86, winding, 85, ground, closing the 30 to 87 contacts. At this point, releasing the push button does not open the winding circuit 85, 86 because this circuit is powered from 87.

Latching a relay can be useful, and combined with the use of the normally closed contacts 30 to 87a in the cancel section, forms the basis of the replacement circuit but there are a couple of more electrical "tricks" needed which will be described as part of the next post with the main diagram.

[Normk]

Here's the main diagram which I will attempt to describe. Note that this does not include a timer for self cancellation by use of the speedometer inductor but may add that facility later if someone wishes.

The circuit uses three main sections: self cancel using a normally closed relay as described earlier. This section switches power to the right and left sections in order to stop signalling function by use of the stock cancel switch.

Let's review the upper left (LH Turn) section:

It will be seen that the relay uses circuit 87 but not 87a. 30 receives power from the cancel section's 87a circuit allowing the cancel relay to power the LH section's relay unless the cancel section relay is in operation.

It will be seen that the circuit Fusebox signal fuse, Cancel section relay circuit 30, 87a to LH Turn relay circuit 30 is powered but the circuit 30 to 87 is open. Since 87a is not used, there is no power flow in this circuit.

Note that both LH & RH Turn signal sections require a flasher relay but since this is not common trade terminology, I will refer to it "correctly" as a "signal flasher". It will confuse the "real" relay with the signal flasher if I do not use the trade terminology as you can see.

So each section LH Turn & RH Turn has its own signal flasher which requires one additional flasher to the stock system but the circuit is so much simpler this way that it is worth while.

OK, this is one of those "chicken & egg' things so will simply plow ahead and back fill as needed: The Blue/black wire from the handle bar signal switch is connected to the 87 circuit, signal Flasher, diode and 85. Let's assume that 86 goes directly to ground at this point in order to keep the description simpler.

Push the signal switch to the left which powers the Blue/black wire. This applies power to the signal flasher which powers the LH signal light bulbs and, if the switch is held in this position, will go into flashing mode. OK, we could have done this without the cancel relay or the rest of the LH circuit but we want it to operate more as stock.

87 circuit is powered but not from 30 as usual, however this still powers the Flasher, but also powers the circuit: Diode, 85, winding, 86, ground which causes the relay to close 30 to 87. Releasing the signal switch opens the circuit Blue/black but the relay remains latched because 30 to 87 is now powering 85 by way of the diode.

The signal lights on LH Turn flash until the cancel button operates the cancel relay and opens that 30 to 87 a circuit.

Got that? Not nearly as complicated as your wife asking if you like the way her new slacks fit, right. There's no right answer there...

OK, let's look at the remainder of the LH Turn's relay winding circuit from 86: The problem with simply grounding 86 is that the relay would remain latched until the cancel relay opens or the key is off. This might be your preferance as it would allow 4-way flashers simply by activating both RH & LH Turn without operating the cancel switch. If this is your wish, simply omit the wire between each 86 and the other Turn flasher unit and ground the 86 terminals.

OK working from the LH Turn's 86 terminal, note that the circuit to the RH Turn signal flasher connects down to 87 (open to RH 30 because this relay is not closed) but does lead through the signal flasher to the signal bulbs and from there to ground. In this fashion the relay's 86 terminal is grounded and the relay operates as normal.

Here's the fun part of this one: with LH Turn in operation, operate the RH Turn signal switch on the handle bar. This powers Green/black and applies power to the RH Turn 87 and Flasher, beginning operation of the RH Turn section. OK, but now we have the same voltage potential on both the LH Turn's 85 & 86 terminals so there is no voltage difference to cause a current flow through the LH Turn relay's winding. The LH Turn's relay opens and shuts off LH flashing. The signals cancel as intended originally, by either, key off, cancel switch or signal to the other direction.

Feedback anyone?

[cowboyup3371]

I started to read it but didn't get all the way through it yet. Sometimes this stuff hurts (yet I can read Cisco Press networking books without too much of an issue) so it takes me awhile to get through it.

But I wanted to say you do realize you can post all of those pictures full-sized in one post by using Photobucket or something similar, right?

[850GT_Rider]

So if I follow the logic, you hit one button to start the turn signals, then hit another to cancel them? If so, (a) how is that "self-cancelling" (b) how is that easier than just turning off the first switch?

I'm confused.....

[Normk]

I don't use Photobucket. Is it an on-line storage?

This stuff is so much simpler than anything in Cisco as to be laughable.

It may have been better to have worked the explanation through smaller steps but find I run out of energy.

I started to read it but didn't get all the way through it yet. Sometimes this stuff hurts (yet I can read Cisco Press networking books without too much of an issue) so it takes me awhile to get through it.

But I wanted to say you do realize you can post all of those pictures full-sized in one post by using Photobucket or something similar, right?

[Normk]

The intent was to utilize the original signal switch for the 1979. The switch is a momentary on for right or left signal with a momentary on for cancel. Some time ago we were discussing a replacement circuit to allow those with a failed Suzuki module an option which would duplicate, to a reasonable degree, the original.

Unlike many bikes which use a signal switch which is simply placed into the on position for right signal, off position for cancel/off, or on position for left signal, the Suzuki uses momentary (like a push button) switching for each selection with the module remaining in the mode of operation last selected until another signal is sent. In other words one cannot turn off the switch using the Suzuki bar switch pod. That is why another solution which allows the original switch pod to be used with the signals was needed. It might be debated as to whether it would be easier/cheaper to replace the bar switch unit with one using on-off-on but that would mean the bike was not longer stock in appearance or operation. This is a concern for some running with collector plates, etc. (Hope this doesn't sound as though am taking exception to your points as they are valid. Just attempting to explain the motivation.)

The only difference between the circuit shown in my diagram and the Suzuki module (from an operation stand-point) is the mine does not auto cancel after a set time. As mentioned in one of the posts, that would be possible but not something I prize so hadn't gone into that aspect.

If someone wishes to have such a feature, I will think about an economic solution. I was simply attempting to provide an option which anyone could assemble at modest cost.

I'm not sure if that addressed your question?

So if I follow the logic, you hit one button to start the turn signals, then hit another to cancel them? If so, (a) how is that "self-cancelling" (b) how is that easier than just turning off the first switch?

I'm confused.....

[rustybronco]

The automatic mode of cancellation makes use of a small inductive winding or coil of wire in the speedometer head, which is connected to the signal light module. A magnet, afixed to the speedometer drive, induces/generates an AC voltage in the winding/coil when the bike is in motion. .

Negative... The component in the speedometer is not an inductive coil, it is a reed switch. It doesn't generate voltage, it is a simple make or break magnetically operated switch which opens and closes four times per revolution..

[Normk]

Thanks for catching that wrong assumption on my part. I had not put my oscilloscope onto the speedo output and made a wrong assumption that the strategy used was typical of these types of systems.

It might be easier to use the reed switch to operate a counter for the purpose of intiating self cancellation than to use an inductor or Hall Effect so the information is doubly positive. The downside is that reed switches are less robust/reliable than are inductors, because of the electrical make and break, which may relate to failures.

Not feeling very positive about the experience of posting this item so will likely drop further postings.

Negative... The component in the speedometer is not an inductive coil, it is a reed switch. It doesn't generate voltage, it is a simple make or break magnetically operated switch which opens and closes four times per revolution..

[rustybronco]

Not feeling very positive about the experience of posting this item so will likely drop further postings.

Why is that? If it works as intended, it's a nice simple solution to a rather large problem.

As I have LOTS of relays and diodes and if I get the time over this weekend, I'll wire it up and see how it goes.

[850GT_Rider]

The intent was to utilize the original signal switch for the 1979. The switch is a momentary on for right or left signal with a momentary on for cancel. Some time ago we were discussing a replacement circuit to allow those with a failed Suzuki module an option which would duplicate, to a reasonable degree, the original.

Unlike many bikes which use a signal switch which is simply placed into the on position for right signal, off position for cancel/off, or on position for left signal, the Suzuki uses momentary (like a push button) switching for each selection with the module remaining in the mode of operation last selected until another signal is sent. In other words one cannot turn off the switch using the Suzuki bar switch pod. That is why another solution which allows the original switch pod to be used with the signals was needed. It might be debated as to whether it would be easier/cheaper to replace the bar switch unit with one using on-off-on but that would mean the bike was not longer stock in appearance or operation. This is a concern for some running with collector plates, etc. (Hope this doesn't sound as though am taking exception to your points as they are valid. Just attempting to explain the motivation.)

The only difference between the circuit shown in my diagram and the Suzuki module (from an operation stand-point) is the mine does not auto cancel after a set time. As mentioned in one of the posts, that would be possible but not something I prize so hadn't gone into that aspect.

If someone wishes to have such a feature, I will think about an economic solution. I was simply attempting to provide an option which anyone could assemble at modest cost.

I'm not sure if that addressed your question?

Yes, you answered the question. Apparently, the difference in our bikes created my confusion.

The turn signal switch on my '80 850 has multiple positions - both momentary and maintained contact. Since my bike came to me with just a standard turn signal relay and no auto-cancel control unit, I've always just used the switch as a standard on/off switch. I'm not sure if that was a change from '79 to '80 or if your switch is defective. I'm sure someone else will weigh in.

[rustybronco]

The system Norm is referring to is the 1st generation self cancel unit and uses a three position momentary contact left hand switch. Your bike is the 2nd generation unit which uses a five position left hand switch.

They are two completely different systems.

Up to 79 was 1st gen, 80 up was 2nd gen.