95 Bonnevile Intermittent Overdrive

Hello, My 95 Bonneville has an intermittent overdive problem that seems to be connected to the cruise control. The car's overdrive sometimes operates and sometimes does not at freeway speeds. I've noticed when the overdrive does engage, the cruise control works. When the OD wont engage, cruise control is inoperative. Once in a while the overdrive will stay working (1/2 day). Any ideas?

The problem was a mis-adjusted switch at the brake peddle that disables thr cruise control and the overdrive. Upon vibration, the switch was disengaging the OD and CC.