Your vehicle may be equipped with a 24 Volt Accessory Power circuit. The connector (A) is located in the engine compartment on the driver's side rear corner of the vehicle under the fender support brace (B). The circuit is identified with a label stating 24V AUX. The circuit is protected by a 25 amp fuse. The accessory side of the connector is supplied, the terminal for that connector will be needed. Contact your GM Goodwrench dealer for this part.