I have been having a problem that has been getting progressively worse over time with my cruise control. It is very difficult to get it to engage and sometimes for no reason it just cuts off. I have to move the switch from off to "set" while pressing the cancel button sometimes for a few minutes before it finally engages. It started several months ago, but back then it would just cut off occasionally and it would take a few tries to get it to engage. Any ideas on what to check here?