I was bouncing along I-10 in southwest New Mexico/southeast Arizona a couple of days ago. When I went over a particularly large bump the cruise control disengaged. This happened several times over the next several miles, it was a bit of a nuisance. I thought there was probably an accelerometer that was getting weak. As I continued along that mindless stretch of highway I thought about how, even after over 17 years and 100,000 miles in this coach, I really knew nothing about the cruise control system. Where were the brains of the system, where was an accelerometer and where were all the wires and connections that could chafe or come loose.
As I continued the problem got worse with the cruise disengaging very often. I tried turning the cruise off then back on but that made no difference. I finally gave up on it and drove on without it, figuring I would work on it when I got to a stopping place. (I am sure many of you have already figured out what was wrong, but not me.) After a while, out of the corner of my eye, I noticed a couple of red flashes down to my left. It was the light on the retarder switch. The retarder joy stick had vibrated back from the off position and would just tickle the number one position with every bounce, disengaging the cruise control.
Moral of the story: If your cruise control acts crazy, think first of the retarder.
For me, I will now try to find out if there is, in fact, an accelerometer in the system and where the brains are located.
There in no accelerometer in the system. The cruise disconnects when the brake lights or disconnect switch on the smart wheel find ground. Period. Probably a bad connection at the retarder joy stick? Start with the simple (and cheapest) stuff first.
Rich and Jan, it was great seeing you during your stop over at the SKP Ranch. Hope to see you at Q next year. I've had the retarder joy stick pounded one notch on a bad road. Very confusing. I've also not turned it off completely with the same results.
A few times I had the cruise keep on disengaging and it was the joy stick not pushed all the way back.
I had a similar problem when the telescoping steering column came up with a thud and dislodged the ground in the column.
Is the horn still functional ?
My situation was purely the position of the joy stick. Hopefully I will remember that next time my cruise control gives me grief. And Woody, thanks for the info about no accelerometer.
Driving down the highway with joystick not-in-off position usually turns on retarder when throttle pedal is released. This can be desirable.
But if also driving under cruise control, when retard turns brake lights on, cruise turns off and remains off.
Some have added a handy dash switch to optionally prevent brake lights from turning on when retard is active.
When driving under cruise control, every dip in the road usually momentarily brings throttle to zero, and at bottom of dip, cruise will increase throttle to maintain set speed. If retard turn on brake lights, cruise will not start back after dip.