New cruise control get flaky with time/miles

[radman]

Heat wrap only delays the inevitable-it will not prevent the unit heating up if it's in a constant heat environment, and it will delay it's cooling once the heat source is gone.

 

[rfulcher]

Warning long post with lots of opinion. May be skipped as the hypothesis is to be tested next week. Those with little tolerance of opinion, conjecture, and rambling might skip to the last paragraph.

I have a suspicion that a very few servos are marginal. Mine performs better with steps to increase negative pressure and maybe with lower temps. It will only cruise at 80+ speeds for a few miles, tolerates inclines poorly, and will only resume if the resume is "easy." As I optimize the linkage and vacuum the improvements are only incremental. Using engine braking or idle with the clutch in postpones but does not prevent degradation. Electrical systems changes have not had a noticeable effect. It holds speed around 60 or less okay but still acts weak even at 60. Hold speed tends to drop as time/miles pass. speed. I had an AVCC on my Concours with a vacuum canister and 2 ports. It would run at 90+ all day long, 2-up, fully loaded, climbing mountains, and resume always worked. I was never able to make it fail. This one consistently fails when the physical demands on the servo are higher.

I am sure the actual vacuum from the bike is adequate since if have tried all kinds of vacuum systems from one port and no canister to 4 ports with 4 check valves using 2 different canisters. Good vacuum with weak servo is my suspicion.

Unfortunately it is a somewhat complicated install with lots of room for error. I suspect there are a lot of installation errors and very few, (maybe no) bad servos. In fact in all of my web searches there is no mention of servo failure outside of this thread. Most problems are "mine won't work" then "try this, test that" and then "found the problem, thanks."

I have yet to find a post where installation of only the servo fixed a problem.

I will receive a new unit later this week and hope to install next week. I will start with just the servo, if that does not fix the problem I will start a very careful install of each subsystem, testing as each component is added. I am worried that the new unit will not fix the problem. I will deal with that if and when.

Alex

How about a better description or pictures?? This sound cool.

"I found a way to get the servo cable on the same cam as the stock cable. Works like it came from the factory. I hated the beads and drilling solution, it just felt unreliable. I feel it is trying too hard to keep the throttle at the correct position. Sounds to me like I need to unwind the center spring, but some say even that doesn't help.... I'm lost."

 

[Inlaw1]

Sounds to me like I need to unwind the center spring

I don't think that's going to do anything for you. I haven't unwound the spring and when my cruise works it pulls like it's supposed to. Up hill, two up loaded it'll resume to the preset speed no problem.

 

[Inlaw1]

I will receive a new unit later this week and hope to install next week. I will start with just the servo, if that does not fix the problem I will start a very careful install of each subsystem, testing as each component is added. I am worried that the new unit will not fix the problem. I will deal with that if and when.

Please be sure and let us know how that goes. I'm very interested in how this turns out. If all that does nothing for your problem you may even want to look at how you have the cable attached, since it's the one deviation from the majority of installs.

 

[rfulcher]

I will receive a new unit later this week and hope to install next week. I will start with just the servo, if that does not fix the problem I will start a very careful install of each subsystem, testing as each component is added. I am worried that the new unit will not fix the problem. I will deal with that if and when.

Please be sure and let us know how that goes. I'm very interested in how this turns out. If all that does nothing for your problem you may even want to look at how you have the cable attached, since it's the one deviation from the majority of installs.

How does my cable install differ from the majority? I think my cable install is very standard, small button head screw, beaded chain on an eyelet, eyelet swings freely, 7 beads I think, parallel connector connecting servo cable to top throttle cable, about 0.2 slack, etc.

Ross

 

[BrunDog]

I will bet my left nut its the servo module itself. Nothing else makes sense.

But for ***** and giggles, I would follow Alan's instructions: connect a vacuum gage in parallel with the servo vacuum, and see what it is seeing. Everything else is just guessing.

You can buy these things at auto parts stores, sears, etc.

-BD

 

[smitty141]

On one of the units I am having problems with, I did this the other day...

Swapped out the board in the servo... nothing, same problem

Swapped out control pad.... nothing, same trouble

Swapped resister in Blue "coil" wire... Still not fixed

Changed vacuum check valve.... Same story..

Soldered "blue" wire to the Gray with red tracer.... Someone hand me a gun, can't take much more..... nothing...

The only thing left to change is the servo itself... I will do that soon.

Smitty

 

[dtyo]

It seems the performance/operation of Alex's system is much worse than mine. I've been trying to use it every opportunity I can get, and it won't fail. I even used it on a road with some pretty steep hills at 45 MPH in top gear and it never quit. I did go over the entire installtion over the weekend and verified every hose and connection. I even used a vacuum pump on the line from the engine to the servo/AVCC and was able to draw and maintain a decent vacuum. One change I made when I was putting everything back together was to put the heat shield in place with the AVCC wiring harness on top of it, isolating it from the heat and electrical noise of the motor - basically one of those "might help, can't hurt" kind of things. An interesting piece of information that I read from one of the replies to this thread was the description of the 3 types of control valves that are (might be) in the AVCC. One for vacuum, one for controlled venting (release) and a dump valve which was described as a fail-safe release for the servo - or at least that's how I read it. I had described how I felt that when the AVCC "failed", it released very quickly vs. a slow let-down of the servo during a "normal" release. Not that it makes a lot of difference, but if this valve does exist, and it only operates during a fault condition, it might help narrow the possible causes of the AVCC failing. I really wish there was some way of getting some kind of status out of the controller itself - anyone got AVCC schematics?

Dan

 

[rfulcher]

Smitty,

You have done the test/verifications outside of the servo that I haven't done yet. Solder grey with red wire to blue, replaced resistor, replaced control pad, etc. This is some comfort that this is not an issue with my install . My AVCC releases hold quickly when it fails, it does not drop speed slowly or sag prior to failure. Is your failure mode similar? Weird how it can run 90+ for a couple of miles and later not hold 65.

I am hoping for a mechanical flaw, maybe a sealing issue in the servo air valves.

I am out of town this weekend and the weekend after plan on a weeklong mc trip, 4 of these day riding double in the Smokey Mtns. Won’t have much time fao a second install but I would really like to have the Audiovox working.

Ross

 

[Inlaw1]

How does my cable install differ from the majority?

Oops, sorry. Got my wires crossed as to whom posted what. It was Alex and his cable install I was thinking of.

< church lady voice > Never mind!! < /church lady voice >

 

[Constant Mesh]

rfulcher --

You mentioned in your first post that your CC power is obtained from:

"Power lead to blue connector switched hot wire under left fairing."

What is the color of the wire that you're tapping for power? I'm assuming its an unused circuit for grip heating.

 

[rfulcher]

rfulcher --
You mentioned in your first post that your CC power is obtained from:

"Power lead to blue connector switched hot wire under left fairing."

What is the color of the wire that you're tapping for power? I'm assuming its an unused circuit for grip heating.

It is a blue plastic connector with two leads and one is a switched lead that supplies power only after the the engine is running. The switched lead I connected to looks green but with the posi-tap in place there is not enough visible wire to see a stripe. As an experimented I have also connected the red/orange fused lead and control pad ground to the accessory plug in the fairing glove box, as with every other test this made no difference.

As an additional experiment I ?might? run the brake system ground to frame and the brake system power lead directly to the battery to totally exclude this system as a variable.

Ross

 

[Constant Mesh]

According to the electrical schematic there are two unused two-wire plugs on the left side. Both of these plugs would connect to the grip heater controller.

Blue plug has two wires:

Red/Black wire = grip heaters switched ground wire

Green/Blue wire = power supply wire to heater controller (switched on when the headlights come on, fed from Headlight relay)

Other plug has two wires:

Black = heater controller ground wire

Light green/White = heater controller wire from ECU

I think the ECU modulates the heater controller based on road speed -- you need more frequent heating cycles when you're going faster.

It would seem that only two of the above four wires is powered. You didn't connect to the Green/Blue wire so you may have connected to the Light green/White wire which may not be good.

 

[rfulcher]

I connectd to a green wire, it migh have a blue stripe, (it probably is green/blue) I can't see enough of the wire to tell about a stripe. It is one of two running to the the blue plug. It comes on with the headlight, if I remember the ground wire to this plug was not black. It was mainly red but I can't remember if it also had black. I refused the impulse to screw with the bike tonight so I am going by memory, sorry about being vague. I thought one of the plugs had a variable voltage, thats why I asked about the blue connector. Sound like I picked a good wire.

However, on the long interstate test ride last night I was powering the unit from the accessory socket in the glove box and it did not change the synptoms.

Thanks, this was good information. This is the kind of info that might lead to a solution. This is a strange problem so it may have an esoteric solution.

According to the electrical schematic there are two unused two-wire plugs on the left side. Both of these plugs would connect to the grip heater controller.
Blue plug has two wires:

Red/Black wire = grip heaters switched ground wire

Green/Blue wire = power supply wire to heater controller (switched on when the headlights come on, fed from Headlight relay)

Other plug has two wires:

Black = heater controller ground wire

Light green/White = heater controller wire from ECU

I think the ECU modulates the heater controller based on road speed -- you need more frequent heating cycles when you're going faster.

It would seem that only two of the above four wires is powered. You didn't connect to the Green/Blue wire so you may have connected to the Light green/White wire which may not be good.

 

[rfulcher]

No joy here

Got my replacement AVCC in the mail today. I am getting good at taking the tank off to get to the mechanical stuff. Installed the new servo. Went for a ride on an empty straight local road. Made 4 passes at 85mph+, each approx 3 miles in length. No malfunction. I could even drop down to 30 in 5th gear and it would resume. I took a break for dinner and then went for a test run on I95. 76-78 mph for about 15 miles with out a malfunction. This is looking pretty good. Turned around at an exit to return home. For 3 miles it was good. Then the problem returned :angry: Over the next 5 miles or so the problem became progressiveley worse. Eventually, after about 25 miles or so, it would not even hold for a minute, it wouldn't "sag" it would just release. The resume function also became flaky whereas it was very strong initially. Using engine braking or idling with the clutch pulled did not seem to help.

The new servo reduced the severity of the problem by 1/2 to 1/3 but the basic problem remains. I might start to replace each of the other components and begin the testing/verification process from scratch. I really thought the problem was gone since it worked so well at high speed and for 15 miles at interstate speed.

I still suspect a bad servo, 2 in a row, how weird, since servo replacement is the only thing to have a significant + effect on the problem.

One thing that I noticed that may or may not be a clue. With BOTH servos the servo end cap at the opposite end from the cable, the end cap the wires go through, was not attached to the servo body with fastners such as screws or rivets. It appears that this cap should the held on by 3 fasteners since there are 3 matching holes in the body and the end cap. This cap will just pull off. On the new servo, the second one, it appears that at least one of the fasteners has been drilled out as the hole is slightly irregular. Am I getting paranoid?

Could someone with a well functioning reliable servo look and see if their servo endcap is mechanically fastened to the body of the servo.

 

[smitty141]

The cap is held on by the metal bracket and three screws. There are several holes, I always rotate the bracket to get the vac port in the best position... Smitty

 

[rfulcher]

Thanks for the info Smitty. Oh yea, have you replaced an entire servo yet?

Ill be gone for the weekend, and back to the problem Monday>

Ross

 

[dtyo]

This isn't what I expected - I would have put money on the servo being defective. OK, here's one more theory - what if a vacuum hose was collapsing; specifically, what if the vacuum hose coming from the engine compartment got pinched off as the engine warmed up and the hose got soft? This would/could explain the degrading performance and eventual total failure. I know this is probably a long shot, but I have doubts that 2 units would fail the same way on the same bike. There has to be something else common with the installation and bike. My AVCC continues to work fine, but I haven't had a chance to operate for more than the 30-40 minutes of my one-way commute - I'm hoping to get on the highway for at least an hour or two this weekend to see what happens. We're working on a process of elimination - I'd vote (like this is a democracy! :glare: ) to replace the vacuum line with a different type or route it in a way to keep it away from any heat sources.

Dan

 

[ionbeam]

what if a vacuum hose was collapsing...got pinched off as...the hose got soft...replace the vacuum line with a different type or route it in a way to keep it away from any heat sources.

Or, tee in a vacuum gauge and actually see what is going on. Bada-bing; bada-boom, done. Not all tubing is vacuum tubing, there is a specific vacuum tube that resists collapsing, as opposed to pressure tubing that resists ballooning.

 

[rfulcher]

When I get back in town after the weekend I will begin the fault finding process again. I will try to get a vacuum guage. I will start to eleminate electrical issues with new parts and verification of connections. I suspect 2 concurrent problems one was the servo and one was/is something else. The second servo is certainly felt stronger than the first, lasted longer at higher speeds and would resume more effectively. 2 bad servos would be strange. Now that I trust the servo more I can start looking for another issue. I suspect a weak servo may it difficult to identify the 2nd problem.

Right now I am away from home and guessing. It will be interesting to see what Smitty finds when he replaces the complete servo.