I own an '89 240 gl wagon with a non operative cruise control. Recently I realized all of my brake lights were not working. I changed the harness that activates the third brake light when I first purchased the car and everything worked fine. I was told by a friend to check the little switch that the brake pedal depresses to activate the lights and activates the cruise control function. A continuity test shows that the switch is not faulty, although the air hose for the cruise control is old and cracked . The fuse in slot #6 is fine. I don't know where else to look. Any hints?