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Murph's Audiovox CCS-100 Servo Mystery

dammitdan

Moped
Hey folks!

I've had a CCS-100 installed on my 2006 C10 for nearly 5 years without issue, until now.

In the process of prepping for an upcoming trip I got a little overzealous with the cruise control servo's pull cable, and the threaded adjustor sleeve at the carb end of the cable snapped.  I tried a repair but couldn't get it to engage. 

I got in touch with Murph and ordered a replacement servo, which promptly arrived and I got on installing.  Swapping out the servo was a simple plug-and-play and all seemed well (slight slack in the cable, no binding and easy operation of the throttle).  But when I took her for a test ride, the CC still would not engage.  Keypad gave no indication that the servo was doing anything.

At this point I pulled it back apart and checked vacuum.  I tested with my finger and a got good pull on the bike>vacuum chamber line, and also from the vacuum chamber>servo line.  So I have good vacuum to the servo.

Next I went at it with a voltmeter and some assistance from the internets.  At the servo's electrical connector I got 12v on the brown and yellow wires when I hit the decel/accel buttons, 12v constant on the green wire when I hit the on button, 12v on the red wire, .08-.10v on purple wire when brake not applied and 12v with brake applies, 10-12DCv on the blue wire when the bike's kill switch is flipped on, and .01 ohms on black.  So I started troubleshooting the servo itself, and this is where things get odd:

Dip switches are set according to the C10 instructions on Murph's site (http://www.murphskits.com/docs/Murphs%20CCS-100%20Installation%20%20Troubleshooting%20Guide.pdf) and the jumper has been removed.  But the red troubleshooting LED only lights up when the decel button is pressed.  No blinking with the bike running, nothing when I pull the brake, nothing when I hit the on/off buttons or the accel button.

So, here's my mysteries:
1.  According to what I've found on the web, I should be getting a lot more from that LED than I am getting.
2.  The super low voltage on the purple without the brake applied *may or may not* be preventing the unit from engaging...  but when I disconnect the purple wire from the bike I got about 8.5v on the wire at the servo.  I'm stumped as to whether perhaps a malfunction at the servo is causing an issue.
3.  The constant DC voltage on the blue wire coming from the tach is strikes me as odd...  I can't find anything as to whether I should be finding anything on this wire.

Tl:dr
My cruise don't work nemore.  Halp!
 

smithr

Member
Member
Its been a few years since I was installing mine but it might be this... from memory...

The new servo may be more sensitive to the grounding of the purple wire to the brake line than your last one.  If mine was not below .1 v it would not engage.  I had to put the relay in to be sure it was hard grounded. 

To prove that is what I needed I did the very unsafe and not really recommended  hard grounding of the wire and taking the bike out to see if it would engage.  NOTE that if you are as crazy as I and try this that the only way to disengage it with that grounded is to turn the unit off.  You might also be able to put in a temporary switch to test this and switch it to grounding only for as long as it takes to see it engage and then back off.

The wire running to the coil has a pulsed signal on it.  If you read it with a DC meter it should have a lower DC value at idle than at higher RPMs.  What you would see on an oscilloscope is pulses though and your DC meter is just sort of averaging them to get the value you see.  If the dc does not change as you rev than it may not be hooked up to the correct place.
 

dammitdan

Moped
I'm going to give installing a relay into the circuit a try.  Maybe the servo is flipped out by the tiny voltage on the purple brake line and isn't blinking the red servo LED for anything but the decel button as a result. I'll let you know how it goes!
 

C14lvr

Street Cruiser
Dan,
Perhaps I can help ya...

First, the blue wire from the servo goes to the NEGATIVE side of a coil. There is a noise suppressor diode factory installed in this wire. It's purpose is to block ignition dirty signals from the coil  from confusing the servo's processor. I've tried to continuity test this wire once, and it will show to be open, yet will be good. So don't let that one throw you. It is absolutely necessary for it to remain in that blue wire...don't remove it. Don't get sidetracked worrying about reading voltage on this wire. Just make sure you've attached it to the negative side of one coil. This gives the servo it's ppm signal.

Second, while some don't install a brake relay when they hook up the purple wire to the brake wire, I highly recommend you do. Using either a 4 pin or 5 pin (disregarding pin 87,) attach the purple wire to the relay's terminal 30. Ground pins 85 and 87A. Switched 12 V positive (from brake switch) to pin 86.
Understand how the relay functions: there's an electromagnetic field coil inside. 12v + to 86 and 12V - to 85 makes it work. The type of relay you'll need to buy is "normally closed" between pins 87A and 30. This means, since we've attached a ground (12 V negative) to pin 87A, internally it's continuous through the relay to pin 30 when the relay is not energized. Ground then flows to the servo through the purple wire. As long as that purple wire is grounded, the servo will work. When you apply the brakes, the relay energizes, it opens between 87A and 30, and the servo stops working. One other note; on the 5 pin relays, when it's energized, it not only opens between 87A and 30, but it closes between 30 and 87. This is why you do not attach anything to 87A! ( One guy did this. He attached 12V positive by mistake to 87A and when the brakes were applied, it sent 12V positive to the servo and blew the circuit board.)

Third, confirm good grounds on the black at the servo and the black at the switch.

Fourth, confirm 12 V switched positive to the red wire from the servo, the switches red/fuse/orange wire, and the switches gray wire.

Fifth, don't worry about reading voltages on the brown,yellow, or green wires. These just connect between the servo and the switch.

Sixth, there are a pair of gray and black wires at the servo. These you remove and discard. They are for applications that require a magnetic speed coil sensor. Yours doesn't.

Dip switch settings: 1-on 2-off 3-off 4-off 5-off 6-off 7-on.

Also, it's recommended to use vaccuum check valves in the vaccuum lines. Make sure they are good, and installed the proper direction. Make sure your vaccuum canister has no leaks. Check valve part numbers at NAPA- 730-1347.

Normally closed 5 pin relay- Murph'skits - MU-141. Check ones bought at auto parts stores. Most of those are normally open, and work the opposite way you want for this wiring configuration I've explained. Many have wasted lots of time scratching their heads as to why it won't work...

Also- if you're not using a brake relay, and you've installed either LED brake light bulbs or an attention getter electronic brake light flasher... this can cause one not to work. Installing a relay solves this.

The only other thing to verify would be if water has gotten in your switch and corroded it. Might remove your switch cover and check. If it's powder sugar white inside, that's a bad thing... Lol.

Hope this will help you solve your "mystery."
Bob
 

dammitdan

Moped
Well, I got the relay installed and still have no joy...  Here's my new readings:
Battery state: 11.66v
Purple wire (brake switch now run through Murph's 5-pin pigtail): 0.0v normal, 10.3v w/brakes
Red wire (power): 11.65v normal
Brown wire: 0.0v normal, 11.08v w/decel button
Yellow wire: 0.0v normal, 11.35v w/accel button
Green wire: 0.0v w/keypad off, 11.33v w/keypad on
Black wire (ground): 0.0ohms to neg. battery terminal
Blue wire (tach): 0.0v w/handlebar kill switch off, 10.23v w/kill switch engaged, voltage decreases with increased RPM

The red LED inside servo continues to only light up with a DECEL button press...  No other flashing.  What do you think?
 

millerized

Crotch Rocket
First off, your battery seems to be shot. Should be 12+ with the bike off, 13+ with the bike running. Most automobile systems are designed for 14.4V, 12B being the sum of the plates.
Charge your battery, and try again.
 

C14lvr

Street Cruiser
millerized said:
First off, your battery seems to be shot. Should be 12+ with the bike off, 13+ with the bike running. Most automobile systems are designed for 14.4V, 12B being the sum of the plates.
Charge your battery, and try again.

I agree with this, Dan.
A fully charged, good 12V. battery should show a resting voltage of around 12.6 volts.

When they drop below the 12V. level, things stop working correctly.

(This is assuming I understood you correctly that your sub-12v. reading was taken at the battery, right?)

I also agree that after first starting the bike, my 2011 will show 14.3 volts for a few minutes, gradually falling to around 14V., running.

Do you have a schematic for the cruise wiring system? If not, I have one I can email you.

If every wire checks correct, and your battery is showing the good, fully charged 12.6V.,and it still refuses to work, then you may be dealing with a defective servo. I have seen a few of these with blown circuit boards. If that turns out to be the problem, it is easy and fast to swap out a circuit board from the servo, without having to remove the entire servo and throttle cable. You just have to buy another servo, which costs about $80.

Any 12V. positive power that accidentally gets applied to the purple wire that's supposed to only send ground into the servo WILL blow the circuit board. I've seen this on a few.

There are Orings inside the servo, when you take it apart to swap a circuit board. You have to be careful not to loose them, make sure they are in their correct place, and check them for damage.
Usually, after the bike has ran and been shut off, I'll pull the vaccuum hose off the servo. If a lot of vaccuum escapes, then those Orings are sealing well, and your OK. Easy, quick check, before taking one apart.

Pm me your email address if you need a schematic.
Bob

 

dammitdan

Moped
Well, I still have the old servo (which should have a good board), so I'm going to try to do a circuit board swap.  I agree that the voltage is low (the battery state reading was taken directly from the terminals).  I've been leaving it on to test the CC servo more than I should, and it has been a few weeks since I trickle charged the battery.  It's less than a year old, glass mat sealed, and gives me 14.5 while I'm riding and was 12+ before I started diving into this latest mystery.  I'll let you know how the circuit board swap goes!
 

C14lvr

Street Cruiser
DammitDan said:
Well, I still have the old servo (which should have a good board), so I'm going to try to do a circuit board swap.  I agree that the voltage is low (the battery state reading was taken directly from the terminals).  I've been leaving it on to test the CC servo more than I should, and it has been a few weeks since I trickle charged the battery.  It's less than a year old, glass mat sealed, and gives me 14.5 while I'm riding and was 12+ before I started diving into this latest mystery.  I'll let you know how the circuit board swap goes!

Ok Dan!
Please keep us posted on the outcome.
Here's a diagram. Hopefully it will show clear enough for you to see it. If not, pm me.
Good luck!
Bob

 

rwulf

Member
Member
C14lvr a question for ya. Where is this diode in the since lead (purple wire) ?
I started having trouble with my cruse control last year. Have checked and
even replaced the key pad to no avail. The purple wire on my bike is and as long
as I've had the bike is just a wire. Anything special about this diode, what way
does it point?
 

C14lvr

Street Cruiser
RWulf said:
C14lvr a question for ya. Where is this diode in the since lead (purple wire) ?
I started having trouble with my cruse control last year. Have checked and
even replaced the key pad to no avail. The purple wire on my bike is and as long
as I've had the bike is just a wire. Anything special about this diode, what way
does it point?

The factory installs that diode about halfway in the length of the BLUE wire, (not the purple.)
The purple is for the ground (controlled by the brake relay) to the servo.
The BLUE has a diode in it, and runs between the servo and any negative side of a coil.
The ones I've seen are shrink booted over. It's purpose is to block interference signals from reaching the servo's circuit board (which would confuse it,) but still allow the coil pulse signal through.
So far, I have not found any of these diodes bad. But I'm thinking that if one were to fail, it might possibly either block the coil pulses from reaching the servo, or interfere with it by allowing dirty signals to reach the circuit board and confuse it.
I do know that if you try to perform a continuity check from one end of the BLUE wire to the other, (even though it IS good) it will show open. Don't let this throw you. Do not remove that diode.
If you did happen to have a bad diode, I would order a new BLUE wire from Rostra, and replace the entire wire.
As far as directional placement, I'm not sure about that. Sorry.

If your cruise system is wired 100% according to the above diagram I've posted and still fails to work, you may have a bad board in your servo, too. But vaccuum problems can also be a culprit. You might go back a few posts and read the list of things I mentioned previously to troubleshoot yours.

BUT... please note... There have been some C10 owners I've recently discovered that wired their cruise systems without installing a relay in the brake wire. THEN, later on, they add LED's in their brake lights or a trunk, and that can mess things up. It shouldn't, though, if you've used a relay.

Bob
 

rev ryder

COG Executive Director
Member
If per chance you had trimmed the wire and lost the diode, I would suspect the diode could be replaced with a 1N4004 or thereabouts.  It needs to tame the flyback signal which can often hit 300v.  Install it with the band towards the coil.
 

C14lvr

Street Cruiser
Rev Ryder said:
If per chance you had trimmed the wire and lost the diode, I would suspect the diode could be replaced with a 1N4004 or thereabouts.  It needs to tame the flyback signal which can often hit 300v.  Install it with the band towards the coil.

Thanks for the info, Rev!
I had one a few months back I suspected bad, and lucked out by meeting an individual that's a Honda Valkrye guru. He's installed several of these cruise controls on them, and had several "extra" blue wires.
I was able to get one from him, and simply replaced it.

I peeled back the shrink tube from the diode, and the one we had used 4 bands of different colors.
But w/o knowing what each color band equated to what resistance value, I was stuck.
So I cheated, and took the easy way out! Lol.
Bob
 

rev ryder

COG Executive Director
Member
Zorlac said:
It's a 20K ohm 1watt resistor in series with the blue wire IIRC, not a diode.

Really?  I'm kind of surprised at that.  That's a pretty big resistor so I suppose it can do the deed.  I know triggering an ecu or other device off the negative side of a coil usually uses a big diode.  In the case of Fred's bike, I would up having to use diodes tying both coils together and then use a 1K 1w pull up resistor off the + side in order to get a decent square wave signal that made sense to the microsquirt.  Took a lot of experimenting.  We blew up a pile of assorted resistors first though. LOL
 

C14lvr

Street Cruiser
Audiovox calls it a "Noise Suppressor".

So, I guess it is a resistor instead of a diode...
I know a diode is a one-way gate that controls the direction of current flow.
A resistor would filter out unwanted frequencies via a specific resistance value then, right?

When I was a teenager, and was installing car stereos back in the day, there was a transformer-looking device you could put in between the stereo and the ignition feed that would filter out ignition noise and alternator whine. I assume this resistor does something similar, only it cleans up any dirty signal before it reaches the cruises circuit board. Correct?

 

rev ryder

COG Executive Director
Member
That would be correct.  But the noise coming from the coil is BIG noise as in high voltage.  But that's a pretty stout resistor and apparently it doesn't dampen the signal too much.  Using the diode on the neg wire permits the normal signal to come through (it's directional) while eliminating the flyback ring (noise) from coming through. Whatever works, works though. Always more than one way to skin a signal.
 

ddback

Sport Tourer
Rev Ryder said:
That would be correct.  But the noise coming from the coil is BIG noise as in high voltage.  But that's a pretty stout resistor and apparently it doesn't dampen the signal too much.  Using the diode on the neg wire permits the normal signal to come through (it's directional) while eliminating the flyback ring (noise) from coming through. Whatever works, works though. Always more than one way to skin a signal.

Correct me if I'm misremembering this stuff Rev, but a basic resistor is just going to induce a voltage drop - across all voltages that transit that resistor. Essentially reducing the amplitude of the voltage curve, but in a non-linear fashion, and will permit current draw in either direction.

While a diode will (up to it's fail voltage) "clip the peaks" off the voltage curve - only allowing a specific range of voltage across (based on it's triggering voltage). It takes a minimum voltage level for the current to flow, eliminating transient low (or high) spikes. Or am I thinking a transistor (which is really just a couple diodes sandwiched together?) Arrgg... been too long.
 

rev ryder

COG Executive Director
Member
JImBob, you're correct on the resistor.  But a diode is typically like a one way valve.  Up to its limiting voltage it stops the transmission of current one way while allowing full flow the other way.

The good Dr. Zorlac here is one of our resident electronics guys.  He's helped me out multiple times when I was stumped.  I will always defer to him.
 

zorlac

Crotch Rocket
Rev Ryder said:
The good Dr. Zorlac here is one of our resident electronics guys.  He's helped me out multiple times when I was stumped.  I will always defer to him.
I just slit the heatshrink tubing off & used my eyeballs when I put one on the FJR, an ohmmeter on the 100 or 200k ohm scale should be able to tell if my recollection is correct.
 

gbyoung2

Member
Member
Well, I still have the old servo (which should have a good board), so I'm going to try to do a circuit board swap. I agree that the voltage is low (the battery state reading was taken directly from the terminals). I've been leaving it on to test the CC servo more than I should, and it has been a few weeks since I trickle charged the battery. It's less than a year old, glass mat sealed, and gives me 14.5 while I'm riding and was 12+ before I started diving into this latest mystery. I'll let you know how the circuit board swap goes!

Old thread, but did the servo board swap correct your issue? I didn't see any follow up from you to this post. Inquiring minds, and all of that............
 
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