I was on the highway, going up a moderate hill at about 65 mph, and the cruise control "let go" and has not worked since. The feeling was like something released and the speed started to drop, until I pressed the foot pedal. The car is a '90 745 Regina, with 240,000 miles, one-owner, and dealer maintenance since new, although I do a few minor things myself. Any thoughts on what to look at first? Thanks.