Next, remove the underdash panel and check the operation of the brake vacuum-control switch. If your Corvette is a standard, there will be another switch on the clutch pedal. Use a test light or a multi-meter to check the operation of the clutch and brake switches. We removed the switches for this photo, but you can check them in place to make sure theyre adjusted properly. We discovered that our cars brake switch needed adjustment. Thats why the system wasnt working properly.