2005 Dodge Ram 2500 Pickup Owner Manual - Page 300

300 STARTING AND OPERATING A frame mounted hitch of up to Class IV rating, as rated by the hitch manufacturer, may also be installed. With a Class IV Hitch, you can tow a trailer with a Gross Trailer Weight of up to 12,000 lbs (5 443 kg) maximum depending on your vehicle equipment. Connecting Trailer Lighting And Electric Trailer Brakes NOTE: A 4-way trailer tow connector, located behind the bumper, is standard equipment on all Ram pickup models. This connector contains the following vehicle circuits: park/tail lamps, left stop/turn lamp, right stop/ turn lamp, and ground. With the optional Trailer Tow Prep package a 7-way connector is also provided with the following additional circuits: backup lamp, trailer battery and electric brake. NOTE: There is also a 4-way connector located under the instrument panel, located to the left of the brake pedal that is used for the electric brake. This connector contains the following vehicle circuits; power ground, battery, stop lamp switch and electric brake feed. The 4-way is optional with the trailer tow prep package. CAUTION! Adding lights or electrical devices to the headlamp/ park lamp circuit can be accomplished by connecting to the standard 4-way trailer tow connector located behind the rear bumper. The maximum current capacity for the park lamp circuit should not exceed 15 amps total (a typical park lamp bulb can draw from 0.5 to 1.0 amperes of current). No connections can be made to the headlamp switch itself, because it is not designed for high current applications. Connections to the headlamp switch will cause the exterior lights to malfunction.