2004 Jeep Grand Cherokee Owner's Manual - Page 228

228 STARTING AND OPERATING • It is recommended that any hitches installed on your vehicle be factory installed, or installed by a dealer using factory approved parts. Factory approved parts are specifically engineered with your vehicle's performance in mind, including the possibility that it will be involved in an accident. Other hitches may not have been so engineered. Vehicle performance, including vehicle damage in an accident situation, may therefore be different. • If trailer towing is required and your vehicle is not equipped with a trailer tow package, the Mopar accessory towing harnesses are the only approved method to provide for trailer lights. These harnesses are designed to provide current to the trailer lights but bypass the module designed to monitor tail lights. Refer to the package instructions for details. Trailer and Tongue Weight Gross Trailer Weight (GTW) means the weight of the trailer plus the weight of all cargo, consumables and equipment loaded on the trailer when in actual underway towing condition. The best way to measure GTW is to put your fully loaded trailer on a vehicle scale. The entire weight of the trailer must be supported by the scale.