On my 3.0L '88 Caravan SE the cruise control is controlled from the turn
signal stem on the left side of the steering column. There's a button that
slides on the stem with 3 positions. All the way to the left is "off". One
click to the right is "on". One more position to the right is "set". This
third position is spring loaded and returns to the "on" position. The "set"
position sets the cruise control speed to the current speed. As long as you
don't slide the button to the "off" position and you don't press the brake
pedal, the cruise control should take over the throttle when you "set" the
speed.

If it doesn't, then there's a problem with the system. That would include
vacuum and electrical problems.

The owners manual is probably easily obtainable from sellers on eBay.

"Gerwin" <adsl545188 (AT) tiscali (DOT) nl> wrote

I think maybe you have to be going some certain speed other than 0 also,
simply starting it will not work..... hold on if you are doing 0 then you
hit set it would keep you at 0. I am sorry i am wrong.