Wiring switch for cruise control

[ITSec]

OK, gang, here's one where I have an electrical connection question. I'm installing the Rostra electronic cruise control on my Stelvio using the excellent guide published a few years back by one of our members. For a variety of reasons, I am not using one of the Rostra switches, and instead I'm using a Pingel switch on the left grip for the RESUME/ACCEL and SET/COAST functions. However, that still leaves me with the ON and OFF to deal with. I am considering a dash-mounted compact momentary SPDT switch, in essence splitting the designed function of the traditional Rostra switch into two separate switches.

Here's what Rostra gives for a diagram:



Now, the part for the first switch is easy, and the part for the OFF part of the switch isn't too hard to figure either. But where does the other part of the ON circuit go?

On the older vacuum-based servo, you could just bypass the ON/OFF part and have the unit hard-wired ON with the brakes or clutch there to disengage as needed, but I am not sure how that would work on this setup...

Moto, if you're listening, how did you handle this when you used the Pingel on your Griso?

[rodekyll]

I was going to ask you what you decided on for that switch.  Spendy little guy, but sturdy and attractive.  I see it's a normally-open/momentary type.  Is that how the rostra oem control works for on/off?  I thought it was an on/off slider, and the stuff you sent me seems to map out that way.  If my memory is working (don't have a rostra switch handy), that means that the diagram is really showing a two position slider with an "on" position that connects +12 to the brown wire (hot to servo through a fuse) and an "off" position where the center post connects +12 to nothing.  In other words, a standard 1s1p toggle switch.  See how that plays . . .

My only hesitation with the "always on" method is that I use hippo hands and I'm afraid I might accidently toggle something.  So I have a separate on/off toggle switch on the dash with an LED to let me know when it's hot.  I wired it per the diagram.  I'll remind you that you sent me that documentation for a reason . . . .

[ITSec]

Rostra switches are normally always open with momentary closed contacts. On my Norge, I used the Rostra switch until it failed (OK, it lasted 80,000 miles!), and then hard-wired the unit ON and just used a SPDT type switch for the RES/ACCEL and SET/COAST. The older Rostra had less 'logic' in its circuit board, and you could do that. The new unit has more expectations of the wiring and switches, and things like the VSS, neutral safety signal, and so on are more important. As such, the diagram assumes you are using the Rostra switch, and apparently doesn't include an indication of where the ON switch connects to. I may have to see if I can coax my old one into working well enough to trace the circuit with a tester.

I'm hoping Moto will chip in and save me that misery. 

[Phang]

could be Ground/negative?

[rodekyll]

If I can find one of mine I'll pin it out for you.

[ITSec]

could be Ground/negative?

Possibly, but doubtful because the RED feed line on the diagram is designed to feed back along all the other lines when the switches are momentarily closed. If the ON switch dumped the feed to ground, all it would do is create a momentary short which strikes me as weird.

[rodekyll]

Rostra switches are normally always open with momentary closed contacts. On my Norge, I used the Rostra switch until it failed (OK, it lasted 80,000 miles!), and then hard-wired the unit ON and just used a SPDT type switch for the RES/ACCEL and SET/COAST. The older Rostra had less 'logic' in its circuit board, and you could do that. The new unit has more expectations of the wiring and switches, and things like the VSS, neutral safety signal, and so on are more important. As such, the diagram assumes you are using the Rostra switch, and apparently doesn't include an indication of where the ON switch connects to. I may have to see if I can coax my old one into working well enough to trace the circuit with a tester.

I'm hoping Moto will chip in and save me that misery. 

Hmmm.   With all that in mind I reread the map and see the off button as another brake switch.  That sheds a different light on my problem.  Doesn't help with the "on" button though.  I'll find that control unit.

[Moto]

The wiring diagram for the switch from Rostra is misleading.

The BROWN wire (in the diagram) is a feed from pin 1 of the Rostra actuator.

The RED wire goes to the hot side of the bike's brake switch, and is used to detect a ground through the tail light bulb in order to cancel the speed setting when the brake is applied. (The additional circuitry near the tail light in my diagram is needed because the tail light bulb is LED instead of incandescent.)

The BROWN-to-RED switch is to be a normally-open, latching (not momentary) switch: the connection stays on after the button is pushed. This is the proper location for the power on/off switch in your setup. I used a water resistant 679-1099-ND switch installed in my left gas tank wing. The Rostra diagram shows that switch labeled "OFF", and doesn't indicate it has to be the latching, not momentary, type.

The RED wire also feeds the hot sides of the momentary switches that signal "SET" and "RESUME" to the actuator. These two signals come out of the Rostra switch as the DARK GREEN wire (for SET, headed to pin 7), and the YELLOW wire (for RESUME, headed to pin 4). In my setup the on/off switch was separate from the Pingel, so the wire coming out of the cold side of my power switch on the tank wing, headed for the brake switch, also splits to deliver the hot signal to the two Pingel switches for SET and RESUME, which then send the signals to pins 7 and 4.

The button labeled "ON" in the Rostra switch diagram does nothing, and is not part of the needed circuitry.

Hope this is clear enough. If not, just ask.

Moto

[ITSec]

The button labeled "ON" in the Rostra switch diagram does nothing, and is not part of the needed circuitry.

Hope this is clear enough. If not, just ask.

So in the end, the ON switch does nothing at all, and the device is actually already on once the ignition switch is on and power is supplied to the servo? If so, this is a definite change from the earlier design.

[Moto]

So in the end, the ON switch does nothing at all, and the device is actually already on once the ignition switch is on and power is supplied to the servo? If so, this is a definite change from the earlier design.

Power is going to the actuator/servo via its pin 5, so it is "on," in the sense that it is powered up, whenever the ignition is on.

But the cruise control won't operate until the switch labeled "ON" "OFF" [oops!] in the Rostra diagram is closed to connect the RED and BROWN wires: this connection is what powers the SET and RESUME signals needed to engage the control. [EDIT: The actuator monitors the BROWN wire for 12v, and cancels the cruise setting (or refuses to engage it) if 12v is not found.]

[rodekyll]

That's what we call a "plot twist" right there.   

Moto -- You're making my brain hurt.  I'm doing the same job right now and now I'm more confuseder than before. 

I think you're saying the fused brown wire from the ignition feeds the rostro unit and can be constantly hot when the ignition is on?

What then does the light blue wire (2-wire plug, lt B and K wires) do?

Can the brown wire from the ignition and the red wire from the brake hot side be joined together or is the actual voltage drop of the brake switch being measured?

Is the latching (toggle) switch in the brown wire from the fuse or the red wire to the brake switch?  Why?

[Moto]

I just corrected a mistake in my last paragraph above: It is the switch labeled "OFF", not "ON", in the Rostra diagram that has to be closed and maintain contact.

I have to go to lunch, so it will be a while before I can reply. This stuff is confusing for sure.

Moto

[rodekyll]

This has shaken my confidence.  I'm going to have to recheck everything and the battery on my fluke meter is dead.  I hate it when that happens.   

[ITSec]

Power is going to the actuator/servo via its pin 5, so it is "on," in the sense that it is powered up, whenever the ignition is on.

But the cruise control won't operate until the switch labeled "ON" "OFF" [oops!] in the Rostra diagram is closed to connect the RED and BROWN wires: this connection is what powers the SET and RESUME signals needed to engage the control.

And then a final question - is there really any good reason the fused side of the RED wire has to go to the hot side of the brake switch, or can it go anywhere a switched power source can be found? I can't understand why the design is specific to that location, particularly since the VIOLET wire gets isolated by the relay when LED lights are used in any case!

[rodekyll]

I'm wondering the same thing.  I joined the brown and red wire and ran them through a fuse and relay.  The relay is controlled by my on/off toggle switch.  For some reason when the relay is actuated that fuse pops, which is what got me started with the wiring questions.

[Moto]

I think you're saying the fused brown wire from the ignition feeds the rostro unit and can be constantly hot when the ignition is on?

YES [EDIT: This is still true, I maintain, and is how mine is wired.]

What then does the light blue wire (2-wire plug, lt B and K wires) do?

IT IS AN ALTERNATIVE CONNECTOR FOR POWER AND GROUND -- NOT NEEDED

Can the brown wire from the ignition and the red wire from the brake hot side be joined together or is the actual voltage drop of the brake switch being measured?

No, they cannot be joined. The RED wire goes to the hot side of the brake switch to measure the voltage drop. The power supply to the RED wire must come from pin 1 of the actuator, via the RED/BROWN wire, becoming the BROWN wire at the connector, and then going into the Rostra handlebar switch.  The RED wire voltage is being monitored, so that when the brake pedal is depressed this is detected. If the two wires were joined this would defeat the cancel function for the brake switch.

Is the latching (toggle) switch in the brown wire from the fuse or the red wire to the brake switch?  Why?

It could be installed either place. But if it were installed in the BROWN wire from the fuse, heading into pin 5, then the RED and BROWN wires in the Rostra handlebar switch would need to be permanently connected. The RED wire feeds the SET and RESUME switches, along with its other job of providing information about the status of the brake pedal. The BROWN wire from the handlebar, as mentioned, is needed to monitor the voltage on the RED wire.

[Moto]

And then a final question - is there really any good reason the fused side of the RED wire has to go to the hot side of the brake switch, or can it go anywhere a switched power source can be found?

Yes, it goes there to sense when the brake has been applied. It is not seeking a power source! It gets its power from the actuator/servo unit, via the BROWN wire coming into the handlebar switch. The setup is confusing because the RED wire is doing two things: providing a voltage monitoring function on the brake switch, but also feeding current to the SET and RESUME switches.
Again, this was my confusion. The RED wire is being monitored for voltage via the BROWN wire in the handlebar switch. It is not itself providing power. The only reason the RED wire needs to go to the hot side of the brake switch is so that its voltage can be monitored to cancel the cruise setting when the brake is depressed.

I can't understand why the design is specific to that location, particularly since the VIOLET wire gets isolated by the relay when LED lights are used in any case!

The purpose of the relay is to provide a ground that must be at zero voltage. Here is the account of the original designer (SEB, on another board):

The last electrical item is the BRAKE- circuit. All Rostra cruise controls want to see a solid 0VDC ground when the unit is engaged. Any voltage on that line at all is enough to keep the unit from engaging. In the past, the ground was read though the incandescent filament of the tail light. Use the brake and the ground goes away. Guess what? No more incandescent lamps now, just LED�s and no way to get to ground through an LED. The Rostra recommendation is to install a relay to switch the line to ground. However, the LED tail light on the Norge feeds back almost 6 volts when the LED is off. This voltage was not enough to energize a relay but enough to keep an energized relay on. The solution to the problem is a small 12VDC relay to switch the BRAKE- line to ground and a blocking diode to keep the tail light leakage from holding the relay closed.

[Moto]

I'm wondering the same thing.  I joined the brown and red wire and ran them through a fuse and relay.  The relay is controlled by my on/off toggle switch.  For some reason when the relay is actuated that fuse pops, which is what got me started with the wiring questions.

Which BROWN wire? The one going into the handlebar switch, or the one coming through the 10A fuse to the actuator?

One thing we have going for us is my operating installation. I know it works! Do you both have a copy of my wiring diagram? Here it is:




free html images

[Moto]

One word of caution about following my wiring diagram: Someone opined that my cutting the wire from the vehicle speed sensor and then using a VOM to count the pulses may not have worked so well with the newer bikes that have ABS. Something about the delicate nature of the electronics there. I have no idea if that is true, but might investigate more if I did this again. You could always use the magnetically triggered speed sensor instead.

Good luck.

Moto

[Moto]

OK. I looked at my own diagram more carefully and then went out to my bike to test for voltage. I found none on the wire from pin 1, contrary to what I had said before. So the 12v is coming from the brake circuit, which is obvious enough, I see now.

Nonetheless, I have (and I believe that you need) a latch-type instead of a momentary switch between the RED and BROWN wires in the Rostra illustration. This is the switch labeled "OFF" in their diagram. The switch labeled "ON" does nothing.

The RED wire from the brake hot side shows 12v until the brake pedal is depressed, when the current draw through the brake light bulb reduces it. The actuator watches for this through pin 1, via the BROWN wire in the Rostra handlebar switch diagram.

The actuator also watches for 12v signals coming from the handlebar via the DARK GREEN wire (for SET, headed to pin 7), and the YELLOW wire (for RESUME, headed to pin 4).

That's about it, except for the gimmick with the relay in the tail light circuit, which I already covered.

Sorry for the confusion. I spent a lot of time figuring this out, but it was over four years ago and I forgot the details.

I'll go back through my previous answers and cross out the parts I now think were wrong.

Again, good luck. I remain yours truly, a sociologist, not an engineer.

Moto

[rodekyll]

I'm going to have to tinker on my connections some.  My red and brown are joined.

Oh -- I'm using a 3-wire sensor to magnets on the drive shaft.  Do I connect the signal to the gray sensor wire?

[Moto]

I'm going to have to tinker on my connections some.  My red and brown are joined.

Oh -- I'm using a 3-wire sensor to magnets on the drive shaft.  Do I connect the signal to the gray sensor wire?

According to the manual, yes.

Also you will need to set a dip switch to expect a sine wave instead of square wave signal:

Programming Switch# 10. It should be OFF to indicate Sine Wave Input.

Moto

[ITSec]

One word of caution about following my wiring diagram: Someone opined that my cutting the wire from the vehicle speed sensor and then using a VOM to count the pulses may not have worked so well with the newer bikes that have ABS. Something about the delicate nature of the electronics there. I have no idea if that is true, but might investigate more if I did this again. You could always use the magnetically triggered speed sensor instead.

Good luck.

Moto

The guide for the Stelvio discusses where to splice into the ABS wiring harness in order to get a usable speed signal, and provides the dip switch settings to match. On my older Norge with the older vacuum-based cruise servo, I used the coil signal - but for my Stelvio I'm using the grey/white wire from the ABS harness as specified in the guide.

[Moto]

The guide for the Stelvio discusses where to splice into the ABS wiring harness in order to get a usable speed signal, and provides the dip switch settings to match... for my Stelvio I'm using the grey/white wire from the ABS harness as specified in the guide.

That's good news. Where is this Stelvio installation guide? Do you have a link to provide? It sounds like it would be relevant for Griso 1200 riders too.

Moto

[ITSec]

That's good news. Where is this Stelvio installation guide? Do you have a link to provide? It sounds like it would be relevant for Griso 1200 riders too.

Moto

It's in the library over at Guzzitech, open to members there. I avoid posting direct cross-references on either board out of respect for their operators. A search on that board for NTX cruise will bring it up.

[ITSec]

I'm wondering the same thing.  I joined the brown and red wire and ran them through a fuse and relay.  The relay is controlled by my on/off toggle switch.  For some reason when the relay is actuated that fuse pops, which is what got me started with the wiring questions.

Did you get this solved? Right now I think I'm copying you, since my 4 amp fuse is blowing when I throw the switch.

I'm having to forget everything I thought I knew from the older vacuum-based system installation.

[rodekyll]

No, I have to dig the servo out from where it lives to access the harness and dips switches.  So far my hands aren't up to it.  I'm hoping to get a chance at it this PM or tomorrow.

Yeah, I may have mentioned a passing familiarity with the old vacuum systems.  My head is muddled.  I'm going to pull the whole business and rewire it.  In a perfect world that should take about an hour, right?

[rodekyll]

I've got LED tail lights which is going to require that extra relay.  This is getting complicated.

[edit]  Do I need a relay to get ground, or can I add a resistor to ground (or a tiny incandescent light) to the cold side of the brake switch?

[Zoom Zoom]

Rk,  when I did this to my Norge 10 years ago, I used a diode in the tail light along with a relay that would complete the ground on the purple wire. Without the diode, the relay would not release after you let go of the brake. This was on the old style CC.

ZZ

edit: Now that I'm not using my fone, I'll elaborate a bit. The purple wire needs, (or in my case needed), a ground applied in order to disengage the cruise. So, I used a relay and the power applied to the relay would trip it to complete the ground for the CC. With the LED's, the lower voltage used to light up the tail lights was enough to keep the relay closed until I turned off the ignition. The diode stopped the flow so the relay would release once I let go of the brake. Many thanks to Wayne Orwig who filled in the last puzzle piece with the doide.

[Moto]

Here's a new copy of my wiring diagram with the colors of the Rostra wires noted. I realized that the earlier diagram's reference only to pin numbers wasn't particularly easy to understand.




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Hope this helps.

Zoom Z.'s experience confirms the importance of the relay setup that I just took on faith from user seb on the other forum.

I did not use the Rostra-supplied wiring diagram, which at least contains errors regarding the two handlebar switches. I recommend you ignore it too. My wiring was based on seb's design.

Moto