Press the "on", it "get's ready". Press "set", and it "goes".
Get it...ready, set, go.
I guess i can describe it as this way....you can't put your truck into drive, until you press the brake. Kinda like that. I honestly don't know the right way to describe it.
Might want to check out the big ford cruise control recall......your truck might be affected. But, again...honestly dont know. I know mine was.