If this restricted to the lamp or does the cruise control not work as well?
Did you try it at highway speed and set the cruise? Sometimes it takes some fidlling with the cruise stalk to get it to work. Is this the original cruise or an aftermarket fitment?
Problem could lie in the switch stalk for controlling the cruise, or the cruise control assembly under the hood. Make sure the cruise control unit is getting power (if electric) or has a good vacuum source (if vacuum actuated). Make sure the cables to the throttle are good and tight with no slack in them. You can take the top off the cruise control unit and manually move the throttle and see if the cables move in the unit.
2002 Corolla S, Silverstream, 1.8L 1ZZ-FE (VVT-i)
2003 Matrix XRS, Cosmic Blue, 1.8L 2ZZ-GE (VVTL-i) - RIP
2009 Matrix XRS, Blue Streak, 2.4L 2AZ-FE (VVT-i)
