and by switch, you're talking about the stalk on the steering wheel?

 

I added cruise to mine. Mine is an '06, cargo van, so it didn't have any wiring from the factory.

From my research, the '07 and up had drive by wire and you could just add the column switch and it would work. Also, if you have power windows/locks, etc, then you probably do have the wiring harness under the hood to connect the servo to. If yours is plain like mine, you probably don't.

What I did is add the switch to the column, then went to the junk yard and pulled the servo and all the factory wire harness for the cruise. I believe there are 10 different wires that are included in the harness. Like 5 or 6 go to the fuse block under the hood, a few more to the switch on the column, and one goes to the block under the seat.

What I did is follow all 10 wires to their respective connectors, (donor vehicle) and cut off all the wires, except for the cruise wires I needed. So when I got home, I could pull the wires out of the harnesses and just snap them in to the harnesses on my van. I had the connectors so I knew where to plug them in. It took some work, but is definitely doable if you can find a donor van. Once everything was hooked up, it works perfectly. No flashing the computer or anything.

I hope that helps, I am not sure if I would go all aftermarket the next time or not. It really wasn't too bad though.