2014 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.

Install Electronic Cruise Control on a K75/K100

Cruise Control Disclaimer: This documents what I did in the hope that others might find it useful. Rostra (and other automotive cruise control manufacturers) specifically state that they do not condone the use of their cruise control products on motorcycles. You are modifying the throttle control on a vehicle that is dangerous enough in the first place. Therefore, if you do this then you do so at your own risk and I am not liable for anything that happens as a result of your reading this.

Note: For K1s, K100RS4Vs and K1100s the wiring will be the same but you'll probably need to figure out a different way to hook it up to the throttle linkage since the throttle bodies are different than on a K75/K100. I think the way I did it for my Audiovox CCS-100 installs would work well.

Caution: It's a good idea to disconnect the ground from your battery before performing any electrical work on your bike.

The Cruise Control Unit

In the past I've installed something like fifteen or so of the Audiovox CCS-100 vacuum cruise control units on various K bikes with excellent results.  However, Audiovox stopped making them several years ago and there's still high demand so they usually sell for $175 or more on Fleabay these days. The site Murphs' Kits sells exact replicas of them for $180. (plus shipping I think)

Since I've run out of "spare" CCS-100 units, I decided to have a go at installing an electronic cruise control.  The one I'm installing goes by two names. One name for it is Global Cruise Electronic Cruise Control and the other is Rostra 250-1223 Universal Cruise Control.  They also sell for about $175 plus shipping these days.  However, several months ago I found a new one, without a control switch, on a $99.99 Buy-It-Now with free shipping so I snapped it up, knowing I'd probably need it someday.  In the summer of 2013 I found a turbo K75 to buy so that became the victim for my pilot install of the 1223.

Here's the installation manual: Global_Cruise_Manual.pdf

Control Switch

On my first few CCS-100 installs, I used the control switch that came with it and mounted that above the choke lever. Like so:

Even though I'd filled the control switches with RTV to "waterproof" them, eventually one of them leaked, shorted and failed.  Then I came up with the idea of using windscreen up/down switch from a K1100LT to control the cruise control.  This has several advantages.  First, it actually IS waterproof since it was designed for a motorcycle. Next, it's an OEM switch so it looks like it belongs there, unlike the aftermarket look of the Audiovox or Rostra switch.  Finally, it's ergonomically more convenient to use.

The up button of the windscreen switch functions as the Resume/Accel/"Tap-up" button and the down button functions as the Set/Coast/"Tap-down" button.  "Tap-up" and "Tap-down" allow you to fine tune your cruising speed once the cruise control is engaged.

DIP Switches

As a "universal" cruise control, the 250-1223, like the Audiovox CCS-100, has a set of binary switches which allow you to configure the operation of the 1223 to your particular vehicle and type of installation.  These are located under the rectangular rubber cap on the 1223 control unit. You probably want to do this ahead of time on the workbench.  Up is on, down is off.

This table, from the installation manual, shows how the unit should be "programmed" by setting these switches.

Note: These are the switch settings what seem to work best on a K75C.  Different models that are heavier or have more power may require some experimentation to finetune the switch settings.

Switches 1 & 2 - Gain: These switches determine how hard the 1223 pulls on the throttle when it kicks in. I have them set at ON-OFF. (Low)

Switches 3-6 - Pulses/Mile: These are to set the pulses/mile received from the speedometer sensor.  A K bike speedometer sensor puts out a little under 5,000 pulses/mile so I set these to ON-OFF-OFF-OFF.(4,000)

Switches 7-9 - Pull: Here are the 7-9 settings sorted:

Engine/Setup Timer

7

8

9

Pull

8 Cyl Low

OFF OFF OFF

Slowest

4 Cyl Low

ON OFF OFF

6 Cyl Low

OFF ON OFF

8 Cyl High

OFF OFF ON

4 Cyl High

ON OFF ON

6 Cyl High

OFF ON ON

4 Cyl Extra High

ON ON ON

6 Cyl Extra High

ON ON OFF

Fastest

According to the Rostra website, these switches determine how "fast"  the control unit pulls on the throttle cable.  It's not really clear from either Rostra's manual or website but I believe that this is the correct sort order for these settings.  If it pulls too quickly then you will have a jerky ride. If it doesn't pull quickly enough then the cruise won't be able to accelerate enough to maintain the set speed,  when you're going up a steep hill for example. Low in the table refers to low weight to high horsepower ratio. Start with the lowest setting, OFF-OFF-OFF, and work your way down the table to fine-tune things.

I found that what worked best on my K75 was ON-OFF-OFF. (4 cyl low)

Switch 10 - VSS Source: The speedometer sensor on a K bike is an analog inductive device that generates a sine wav. Set this to OFF

Switch 11 - Transmission: Set this to OFF - for a manual transmission vehicle.

Switch 12 - Control Switch: Set this to OFF. (For either the windscreen switch or the switch that comes with it. Both are normally open switches.)

Function:

Gain Pulses/Mile Pull Sine Man Open
Switch 1 2 3 4 5 6 7 8 9 10 11 12
Setting ON OFF ON OFF OFF OFF ON OFF OFF OFF OFF OFF

Wiring

Power supply: Since the 1223 uses electrical power to pull on the throttle it uses a fair amount of power compared to a vacuum cruise control so I added a switched fused relay to power it.  Using standard Bosch terminal designations, here's how I wired the relay:

Terminal

Connects To
85 Ground
86 Tapped into the green/brown wire of the white four terminal alarm connector found in the relay box. (Switched power from #7 fuse.) This turns the cruise control on when the bike is turned on.
30 Power in. I connected this to the "always hot" terminal on the starter relay with a ring terminal.  I put a 15 amp fuse in this circuit.
87 Red and brown wires of the 1223.

The wiring instructions in the installation manual that came with the 1223 are horrible so I did some poking around on The Internet to gain a better understand of the wiring.

Red Wire: According to the installation instructions you're supposed to hook this up to the "hot" brake switch wire (green/black on a K bike rear brake switch) but that wire is just switched power so I ran that to the relay output power above to keep things simple.

Brown Wire: This is the main 12V+ power to the 1223. That is hooked up to the relay output above since I'm not using a power switch and it will just be on whenever the bike is turned on.

Black Wire: This is the main ground for the 1223. I've read that the 1223 can be sensitive to poor grounding so I connected it to the negative terminal of the bike's battery using a ring terminal.

Violet Wire: When the brake light goes on, this wire senses 12V+ and disengages the 1223. You can tap this into the (gray/yellow) brake light wire. Since I have LED brake lights, I added a normally closed PCB relay that grounds the violet wire when the brake light is not lit.

Light Gray Wire: This wire monitors the pulses from the speedometer sensor so the 1223 knows to speed up or slow down in order to keep you at your set speed.  Tap that into the yellow speedometer sensor wire under the right side battery cover.

94+ K1100s have a slightly different connector but the wire colors are the same - yellow & brown.

Light Green Wire: (Optional if you tap the blue wire into the coil.) This is the Neutral Safety Switch wire. It keeps the 1223 from over-revving if you pull in the clutch or the bike is in neutral.  The 1223 disengages when this wire is grounded. Since K bikes use the clutch switch to put 12V+ to the start button when the clutch is pulled in, I used a normally open PCB relay to send a ground signal to the 1223 when the clutch is pulled in or the bike is in neutral.  I tapped the positive trigger wire for the relay into one of the black/green wires (power to the start button) at the connector for the right combination switch.

Blue Wire: As a safety feature, this wire monitors the RPMs at the ignition coils to avoid the 1223 from going into run-away mode and over-revving the engine. However, since I'm using the clutch switch this wire does not need to be wired to the coils. Per the installation instructions that came with the 1223, I grounded this wire to the negative battery terminal with the main ground wire (black wire above) to avoid it introducing "trashy" signals into the system.

Dark Green Wire: This is the wire for the Set/Coast/"Tap-down" button. I wired that to the blue (down) wire of the windscreen switch.

Yellow Wire: This is the wire for the Resume/Accel/"Tap-up" button. I wired that to the gray (up) wire of the windscreen switch.

Green Wire - Windscreen Switch: This provides switched 12V+ power to the windscreen switch.  I tapped that into the green/brown wire of the alarm connector in the relay box.

Orange Wire: (Optional.) This wire puts out a ground signal for an indicator lamp when the cruise control is engaged.  Since the bike is an 86+ non-ABS bike I wired that up to an amber led I installed in the unused indicator next to the low fuel light in the instrument cluster. I'd wanted to use a green LED for this but wavelengths of a green LED and the red lens are too different to let much light through.  So I used an amber LED instead which works much better as amber and red wavelengths are closer together.

K75s & 2V K100's: Another approach is to use the 1223's orange wire to have your choke indicator lamp in the instrument cluster double as a cruise control indicator.  All you need to do is tap the orange wire from the 1223 into the violet/white wire of the choke switch connector found under the left side of the tank. Even if your K bike is a 91 or later that didn't come with a choke indicator there's still a two wire connector (violet/white and brown) under the left side of the tank that goes to the choke lamp in the instrument cluster. Connect the 1223's orange wire to the violet/white wire.

 

Click on the wiring diagram below to have a larger version open in a new tab for printing:

Wiring diagram from installation manual:

K1100LT Windscreen Switch

The housing of the K1100LT left combination switch is the same as a K75/K100 so it will "bolt right up" to a K75/K100 choke perch. There's a Phillips screw at the bottom middle of the face of combination switch that holds the combination switch on. If that hasn't been removed since your bike left the factory then there can be some corrosion in the threads so be sure to use a good screwdriver and lots of pressure to avoid stripping the head of it.

For the headlight, horn and turn signal, the K1, K100RS4V and K1100 models use different combination switch wiring harness connectors than K75s/K100s.  Therefore, you'll need to graft the connector from your old left combination switch to the K1100LT combination switch with a windscreen switch.  However, both use the same wire colors so it's a straightforward task.

Hardware Installation

Cruise Control Body: I chose to install the 1223 in the tail cowl of my K75. I drilled a hole in the lower left hand corner of the tail cowl for the cable to pass through.

Routing The Wiring: I encase all of the wires from the control unit in an approximately 2 1/2 foot long section of heat shrink tubing to bundle and protect them. (You don't need to heat shrink it.) I run this out of the left turn signal wiring hole in the lower left corner of the tail cowl and then zip-tie the bundle to the left frame rail under the tail cowl, similar to how the factory tail light wiring runs along the right frame rail. Then,  up near the battery, I split off the various wires to where they need to go.

In order for the rear fender to fit on the right rear corner of the frame, I cut a U for the wiring bundle here:

 

Throttle Pull (a.k.a. Servo Cable): I modified the bracket that came with the 1223 as shown here:

.

Once I'd painted it black (while listening to The Rolling Stones) I snapped the black plastic cable holder into the square hole and mounted the modified bracket to the left frame rail with a stainless steel hose clamp above the throttle bodies:

And then attached it to the factory throttle body adjustment screw between the #2 and #3 throttle bodies. DO NOT mess with that screw itself as it should remain where the factory set it. I just put a connector and a nut on top of it, that's all.

I used a ball chain end coupling and installed it as shown:

"Cheat Sheet"

Click on this link for a 1 page installation "cheat sheet:"

 

 

Test Ride

Although it is doubtful that anything will go wrong on your test ride, the red kill switch is your friend.  It is important to note that on K bikes the kill switch cuts power to the brake light so if you're testing it with traffic behind you then the vehicle behind you may not be aware that you are slowing when you apply the brakes after hitting the kill switch.

Troubleshooting

There's a diagnostic LED under the rubber cap to the left of the DIP switches:

 

1. Turn the bike on while holding the up switch of the windscreen switch.  The LED should be off and the 1223 should be in diagnostic mode.

2. Press the down switch of the windscreen switch. The LED should illuminate when the switch is pressed.

3. Press the up switch of the windscreen switch. The LED should illuminate when the switch is pressed. If neither of these illuminate, use a voltmeter to check that you are getting 12V at the windscreen switch's green wire.

4. The LED should illuminate when either brake is used. Check that you are getting power to the 1223 if none of the above actions illuminate the LED.

5. To test the speedometer sensor connection, with the bike in neutral and on the center stand, spin the rear wheel. The LED should flash.

6. To test the Neutral Safety Switch function switch, pull in the clutch. The 1223 should disengage.

Footnote: The cruise control kit comes with several ScotchLok connectors for tapping into existing wires.  I've found these to be unreliable and sometimes they will cut the wire you're tapping into. I prefer to use Posi-Taps for tapping into wires.

ScotchLok

Posi-Tap

PTA2022

2014 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.