2004 Chevrolet Express Van Owner's Manual - Page 23

Shoulder Belt Height Adjuster Before you begin to drive, move the shoulder belt adjuster to the height that is right for you. To move it down, pull on the center adjuster control labeled PULL. You can move the adjuster up just by pushing up on the shoulder belt guide. The lap part of the belt should be worn low and snug on the hips, just touching the thighs. In a crash, this applies force to the strong pelvic bones. And you'd be less likely to slide under the lap belt. If you slid under it, the belt would apply force at your abdomen. This could cause serious or even fatal injuries. The shoulder belt should go over the shoulder and across the chest. These parts of the body are best able to take belt restraining forces. The safety belt locks if there's a sudden stop or crash. After you move the adjuster to where you want it, try to move it down without pushing in to make sure it has locked into position. Adjust the height so that the shoulder portion of the belt is centered on your shoulder. The belt should be away from your face and neck, but not falling off your shoulder. 1-17