Lights will come on for cruse control but cruse control will not engage

Hello, certain components need to be verified as functional to engage the cruise control, otherwise it will not function. For example, the brake light switch must be functional so that when you hit the brake, it disengages the cruise control. If this isn't working properly and consistently, the system will not function. You'll need someone to go through a diagnostic flow chart to find out what is going wrong here. Good luck.