I thought it was just my big clumsy hands, but both of us manage to activate cruise control when reaching for the turn signal. Cutting 3/4″ off the end made all the difference.
Because of the way that Mercedes chose to make it operate, knocking the cruise lever either to the left or the right (down/up) resumes cruise. The van will attempt to accelerate back up to the last cruise speed. Not so good if you pull off the freeway into a residential area and try to signal to turn left across oncoming traffic.
Most other vehicles I’ve owned have a distinct “turn cruise control on” step before the “activate cruise control” step. Thus, you can also turn cruise control off so that whacking the +/- buttons has no effect. As far as I can tell from reading the manual and experimenting, on the Sprinter, there is no way to turn cruise control completely off. Once you’ve enabled it during a trip, it’s got a speed set in its memory. You can stop it from being active, but you can’t turn it completely off.
I put on my “think like a German engineer” hat and went to work on the cruise stalk.
The plastic end comes off in two pieces. First, you remove the cap by gently pulling/twisting and wiggling it. It has tiny plastic detents.
Next, you have to take a pick or other fine ended implement and pull back two tabs in the end of the remaining plastic piece. They lock against milled out depressions in the metal stalk. Once you have them pulled away, the plastic piece just slides off.
That leaves the metal stalk. It has the two milled depressions and also an anchorway cut out at the bottom. The plastic end cap has a corresponding raised section that keys into the anchorway. That presumably stops the end cap from rotating on the stalk. The end of the stalk is also relieved somewhat around its outer circumference, probably to help it slide into the plastic piece.
There are no wires. It’s purely a mechanical lever.
Steve/MercedesGenIn on the Sprinter forum posted a link to the full instructions for adding cruise control. 32 steps, including removing the steering wheel entirely. There was no way I was interested in that type of effort, so I decided to cut it down in place.
First, I used a small cardboard box to form a shield for all the sparks from the cut-off wheel. I stabbed a hole in the end of an Amazon A1 size box and pushed it over the stalk. Glad I did, because it caught a whole bunch of metal filings and stopped sparks from flying everywhere. Hooray for Amazon.
I used a fiberglass reinforced cut-off disk to cut the metal stalk clean off at the paint/bare metal intersection – about 3/4″ in from the end. I figured if everything went wrong, I could just epoxy that end piece back on with a splint in the hollow middle of the stalk and nobody would be any the wiser.
However, it was actually pretty simple to cut the keyway notch and two indents for the retaining clip. I even smoothed the outside edge of the end down a little.
My work doesn’t look as smooth as the original machining, but it holds the plastic end cap on just fine and the cap doesn’t turn or slide on the stalk. All my cuts are hidden inside the plastic end cap. No epoxy required!
The whole stalk is now 3/4″ shorter than before. That’s just enough that my fingers miss it when I’m reaching for the turn signal but it’s still accessible when I really want to mess with cruise control.