1998 Plymouth Voyager cruise control

Cruise control quit while traveling at 70mph on interstate
on the way to Florida. It worked intermitently in Florida and stopped when I returned to Indiana. It began working on the trip home in Tennessee the same place where it quit on the way south

it has steering wheel buttons. The cruise light would come on but the set would not activate. Repeated pushing would make it work sometimes. Other times the cruise light would go off after 1 minute of trying to engage the cruise. Still other times the cruise would work one day and not the next.