See also:

Windows
Press the front of the switch to lower the window. Pull the switch up to raise it. Pushing or pulling the switch part of the way will open or close the window as long as the switch is operated. ...

Footnotes — Maintenance Schedule Additional Required Services — Normal
a) Or every two years, whichever comes first. More frequent replacement may be needed if the vehicle is driven in areas with heavy traffic, areas with poor air quality, or areas with high dust levels. ...

Vehicle Overview
GMC’s full-size van sells in fewer numbers than the similar Chevrolet Express but attracts a loyal clientele. Along with its full-size rivals from Dodge and Ford, the rear-drive truck-based van ...