I had a problem like that years ago when the brake pedal switch went bad. If I remember correctly, there's really 2 switch connections inside the brake switch - one for the brake lights and one to signal cruise control that you touched the brake, which disengages it immediately. You should try replacing the brake switch. That fixed it for me. I just remember it was a big pain to separate the wire plug-in from the switch. I had to use a screwdriver to pry somewhere on it. Check the new switch for where to pry. Be careful in case you don't have brake lights either.