1999 GMC Sonoma Owner's Manual - Page 190

yellowblue Dust or dirt can enter the back of the transmission through the opening created by removing the propeller shaft if proper protection is not provided. Also, check the transmission fluid level before driving the vehicle. When towing your vehicle, turn the ignition to OFF. To prevent your battery from draining while towing, remove the RDO BATT fuse from the instrument panel fuse block. Be sure to replace the fuse when you reach your destination. See "Fuses and Circuit Breakers" in the Index. Be sure to use the proper towing equipment designed for recreational vehicle towing. Follow the instructions for the towing equipment. Loading Your Vehicle The Certification/Tire label is found on the driver's door edge, above the door latch. The label shows the size of your original tires and the inflation pressures needed to obtain the gross weight capacity of your vehicle. This is called the Gross Vehicle Weight Rating (GVWR). The GVWR includes the weight of the vehicle, all occupants, fuel, cargo and trailer tongue weight, if pulling a trailer. 4-40