Audiovox Troubleshooting

[DesignFlaw06]

My Audiovox setup has never worked properly I don't think, but it has worked well enough and I dealt with it. When I hit Set, the speed would drop ~5-7MPH before engaging. It would slowly work its way up to the setpoint. Most of the time I would hit set, but hold on to the throttle until I felt it engage and let go. Resume was also painfully slow and had to be done in a similar fashion. I checked the cruise cable several times and there doesn't appear to be any slack in it. I do have an extra canister, but it never had a huge issue maintaining speed once it was engaged.

Last Tech Day, after checking the slack in the cable again, I decided to move the sensitivity setting to a medium vehicle. Instant improvement. The cruise engaged immediately after pushing the button. It resumed quickly and I was very happy with it. Fast forward to last Wednesday, I was riding across the state and it started disengaging randomly. I was cruising around 85 MPH and then get the sudden lurch when the cruise was no longer working. It happened a few more times on the way, but I figured it might have been due to the speed or maybe the tach signal was too high. And it didn't happen often enough during the 2.5 hour ride to be too concerned about it.

Coming back home on the freeway yesterday, the cruise control problem got much worse. I could get maybe 10 minutes before the cruise disengaged. Maybe the sensitivity setting was too much and won't work at 80 MPH speeds. I stopped at a rest area and changed the setting back to a lightweight vehicle. The sluggishness to the cruise control returned, but the problem didn't go away. I set the cruise down to 70 MPH and it didn't disengage at that speed. Once I increased towards 75, the problem would show up again. It seemed like the higher the speed, the more likely it happened.

I'm assuming that I should be able to run the Audiovox at a cruising speed higher than 70 MPH. Before I dive into the bike to try and diagnose it, what should I be looking for? One thought is that maybe the brake signal is acting up. I'm fairly certain I still have a relay installed for that. That doesn't necessarily explain the higher speed making a difference though. If it's going to save me time, I'll just replace the unit. I'd be more tempted to go with the Rostra at that point. I like the idea of not needing the vacuum. But I don't want to replace it if I don't have to.

Thanks for any help or guidance.

[dcarver]

If you can't fix it, I have a brand new in box Audiovox available for sale.

Troubleshooting...
1. vacuum leak?
2. electrical connections.. brake switch(es), module control connector, etc
3. run up to 80 in 4th gear... to change engine vibe resonances, still thinking wiring, external or internal
4. check the switch pad backside for corrosion

Good luck!

[raYzerman]

There is a (5-way?) Molex connector to the dash switch.... (likely near the steering head) the pins easily push out, yours may have been "OK" until now. Also, whether you need it or not, take the dash switch apart, clean the carbon contacts with contact cleaner (no dielectric grease), put it back together and reseal it with silicone or RTV. If it otherwise functions, those are the most likely areas of concern.... assuming no vacuum leaks.

[dcarver]

There is a (5-way?) Molex connector to the dash switch.... (likely near the steering head) the pins easily push out, yours may have been "OK" until now. Also, whether you need it or not, take the dash switch apart, clean the carbon contacts with contact cleaner (no dielectric grease), put it back together and reseal it with silicone or RTV. If it otherwise functions, those are the most likely areas of concern.... assuming no vacuum leaks.

Yes. Me Too.

[ionbeam]

The Audiovox should work nearly flawless. The unit I installed in my '04 worked better than the OEM in my '15ES. Vacuum control isn't low tech, in fact things vacuum and air powered tend to be smoother and more livable than all electronic units.

The vacuum would like to have two or more ports tapped on the throttle body and have a check valve on each port. Without the check valves it is the equivalent of having all the TBs connected together sharing a common vacuum level -- in essence, no sync at all. A vacuum accumulator (canister) helps with reserve vacuum capacity and smooths vacuum flow. I used a '87 Goldwing fuel filter so that the paper element prevented fuel fumes from possibly back-streaming into the solenoids in the AVCC servo.

Hesitation when setting speed is most commonly too much play in the actuator bead chain. Too little vacuum can cause a problem setting speed but it also comes with massive speed slacking on hills which is a big diagnostic clue. The vacuum servo in the AVCC is surprisingly strong, it should be able to overcome sticking linkages and strong throttle springs with no problem.

With the cover off the back of the servo there is a jumper that looks like a small black plastic rectangular block, it needs to be pulled off and rotated 90 degrees so it only sits on just one pin. This tells the servo the vehicle has a manual transmission. The jumper is typically near the diagnostic LED.

The DIP switches need to be set so that the processor in the servo knows that you have a light weight vehicle with a high power, high revving engine. The serve will then gently pull on the actuator cable so you don't get whacked with WOT as it adjusts speed. Conversely, your '85 Buick needs to be set for heavy vehicle with a nearly dead, low revving engine. The servo won't futz around by softly pulling on the actuator, it goes right after the actuator in a heavy, aggressive manor which would be totally unacceptable for the FJR.

DIP Switch Settings:

1 - ON
2 - OFF
3 - OFF
4 - ON
5 - OFF
6 - OFF
7 - OFF


Switch 4 should be ON, it will effect driveability but won't effect engage/disengage. Setting switch 4 to ON tells the servo that you have a light weight, high horsepower vehicle and to pull and release the actuator cable gently.

Switch 7 should be OFF, the coils are fired by the ECU and not breaker points. When switch 7 is OFF the servo looks for a relatively clean switched signal, when switch is ON the servo uses filtering for very dirty breaker point signals. For some reason the AVCC does not like the Gen II with switch 7 ON. Having DIP Switch 7 ON won't effect initial cruse engagement but when set to OFF it will prevent the cruise control from dropping out unexpectedly and then not wanting to engage again, just what the OP is experiencing. For some reason, the AVCC will initially work satisfactorily with DIP Switch 7 ON, and then gradually start to cause sporadic drop-outs weeks or months after the install was completed.

A lightly sticking brake pedal can cause seemingly intermittent cruise problems. When having problems getting the cruise to set speed when the SET switch is pressed, hook your toe under the brake pedal, lift, then try to set speed again. This has been the source of a lot of AVCC tears.

Problems with the control pad tend to cause 'stuck-at' faults. LEDs are stuck ON or OFF all the time, the cruise won't turn on at all or won't turn off at all, or the Set/Resume stop working completely.

The brake wire can cause problems preventing the cruise from engaging speed control. If the AVCC system has been working, then it is highly unlikely that the brake wire is a problem. This is the item of last resort for troubleshooting, only after all else has been eliminated from an established working system. The only thing the brake light wire affects is the ability to set speed when the SET button is pressed.

[wheatonFJR]

Alan is the king of troubleshooting...

[ionbeam]

Just because I already have these pictures. AVCC control pad:

The control pad doesn't actually contain switches, it uses interlaced gold fingers and a silicone rubber membrane that has carbon dots stuck to it. When you press the 'switch' the little black carbon dot presses on the interlaced gold fingers shorting them together which the AVCC processor sees as the switch being made.


Sealing the control pad.




When the control pad is not well sealed, note the green corrosion in addition to the dirt which has infiltrated the pad:






And, this is the result. Broken fingers and blown LEDs.

[DesignFlaw06]

Switch 4 should be ON, it will effect driveability but won't effect engage/disengage. Setting switch 4 to ON tells the servo that you have a light weight, high horsepower vehicle and to pull and release the actuator cable gently.

Switch 7 should be OFF, the coils are fired by the ECU and not breaker points. When switch 7 is OFF the servo looks for a relatively clean switched signal, when switch is ON the servo uses filtering for very dirty breaker point signals. For some reason the AVCC does not like the Gen II with switch 7 ON. Having DIP Switch 7 ON won't effect initial cruse engagement but when set to OFF it will prevent the cruise control from dropping out unexpectedly and then not wanting to engage again, just what the OP is experiencing. For some reason, the AVCC will initially work satisfactorily with DIP Switch 7 ON, and then gradually start to cause sporadic drop-outs weeks or months after the install was completed.

That's interesting. Wayne gave me this unit a couple years ago and Switch 7 was Off. I was having issues until I turned that switch back to On. Maybe it should have been off all along, but I can't recall the issue I was having before. I'll try switching it back and see what happens.

Pretty sure the control pad is fine. I sealed it when it was installed and if the Off button was being triggered incorrectly, I would have to hit On again each time. I also did away with the Molex connector and the wires are soldered together.

I'll report back, but the weather needs to cooperate for testing.

[DesignFlaw06]

So Switch 7 being set to Off seems to do have done the trick. I went about 125 miles today with no issues cutting out. I do find the medium sensitivity setting to perform better. About the only time it is abrupt is if I am trying to resume while the speed has dropped 30+MPH and I'm not on the throttle at all. That doesn't really happen during regular use.

[ionbeam]

So Switch 7 being set to Off seems to do have done the trick...

Fingers crossed for ya. You should be good to go.