Basically this is a mod that short-circuits the Cruise control relay that requires you to turn on the toggle switch on your dash to the left of the steering column...

What you'll need:
1. A couple inches of 14-gauge wire (16 or 18 might work, but I didn't want to risk the wire melting)

2. A couple crimp-on flat spade connectors

What to do:

Attach the spade connectors to either end of your wire, like this:



Open up the relay box on the passenger side of the engine bay, you're looking for the slot that has ASCD (Automatic Speed Control (Device?):



Remove the ASCD relay from it's slot (a small flat-head screwdriver will help you with the clip that holds it in). Now insert your wire into the connection that is perpendicular to the other 3, and the connection opposite that, like this:




Put the cover back on the relay box and put your unused relay away, cuz you're done. Now the cruise control will be on whenever the car is on.

-Credit: justmax