120 AC/12 DC/LP-Gas – The power sources on which RV refrigerators operate; 120 AC is 120-volt alternating current (same as in houses); 12 DC is 12-volt direct current (same as in motor vehicles); LP-gas. Some RV refrigerators can operate on two of the three sources, others on all three.
Anode Rod – An anode rod, when used in a water heater, attracts corrosion causing products in the water. These products attack the anode rod instead of the metal tank itself. The anode rod should be inspected yearly and changed when it is reduced to about 1/4 of its original size. The rods are used in steel water heater tanks – an aluminum tank has an inner layer of anode metal to accomplish the same thing. Anode rods should not be installed in an aluminum tank!
Axle Ratio – The ratio between the pinion and ring gears in the differential that multiply the torque provided by the engine. It is the number of driveline revolutions required to turn the axle one time. As an example, with a 4.10:1 axle the driveline turns 4.1 times for each full axle revolution. The higher the number, the more torque and thus more towing power. However, the higher the number also means less speed.
Backup Monitor/Camera – A camera in the back of a motor home, with the monitor positioned somewhere on the dashboard for the driver, to aid in backing up the motor home. It is also used while driving to see the traffic behind and to keep an eye on the towed vehicle.
Ball Mount – The part of the hitch system that supports the hitch ball and connects it to the trailer coupler. Ball mounts are available in load carrying and weight distributing configurations.
Black Water – Disposal water from toilet system, held in holding tank until you dump it, in large tanks or dumping station available at most campgrounds.
Black-Water Tank – The black water tank on an RV holds the sewage water from the toilet. This should always be dumped at a campgrounds dump station or into the campsite sewer connection.
Boondocking – Also known as dry camping, boondocking refers to camping without any hook-ups, namely camping without hooking up to any electric, sewer or water facilities. You can still have electricity from your RV batteries and water from your freshwater holding tank.
Brake Actuator – a device mounted under the dash of a towing vehicle to control the braking system of the trailer. Most Brake Actuators a based on a time delay, the more time the tow vehicle brakes are applied the “harder” the trailer brakes are applied.
Brake Controller – a device mounted under the dash of a towing vehicle to control the braking system of the trailer. The Brake Controller senses the amount of braking force of the tow vehicle and applied a proportional force to the trailer braking system.
British Thermal Unit (BTU) – A measurement of heat that is the quantity required to raise the temperature of one pound of water 1 degree F. RV air-conditioners and furnaces are BTU-rated.
Break-Away System – A system designed to automatically lock the trailer brakes in the event of a hitch failure and the trailer breaks away from the tow vehicle.
Camber – Wheel alignment – Camber is the number of degrees each wheel is off of vertical. Looking from the front, tops of wheels farther apart than bottoms means “positive camber”. As the load pushes the front end down, or the springs get weak, camber would go from positive to none to negative (bottoms of wheels farther apart than tops).
Castor – Wheel alignment – The steering wheels’ desire to return to center after you turn a corner.
Condensation – Condensation is a result of warm moisture-laden air contacting the cold window glass. Keeping a roof vent open helps to reduce the humidity levels. Added roof vent covers help to prevent cold air from dropping down through the vent while still allowing moist air to escape. Using the roof vent fan when showering or the stove vent fan when cooking also helps prevent excess moisture buildup.
Converter – A converter is a device that converts 120 volt A/C (alternating current) to 12 volt DC (direct current). The RV devices mostly run on 12 volt DC power that is supplied by the battery, which allows the RV to function independently. When “shore power” (an electrical supply) is available, the converter changes the voltage from 120 to 12 volt to supply the appliances and to recharge the battery.
Diesel Puller – The term for a motor home with the diesel engine mounted in the front of the vehicle. Also known simply as a Puller.
Diesel Pusher – The term for a motor home with the diesel engine mounted in the rear of the vehicle. Also known simply as a Pusher.
Dinghy – The term for a vehicle that you are towing with your motor home. It is also known as a Toad.
Dinette – Booth-like dining area. The table usually drops to convert unit into a bed at night.
Doughnut – A rubber ring that seals one’s dump hose and the campsite sewer connection so that gases and odors do not escape. Sewer doughnuts are required in many locations.
Dry Camping – Also known as boondocking, dry camping refers to camping without any hook-ups, namely camping without hooking up to any electric, sewer or water facilities. You can still have electricity from your RV batteries and water from your freshwater holding tank.
Dry Weight – The weight of the RV without any fuel, freshwater, propane, or passengers.
DSI Ignition – direct spark ignition – this term refers to the method of igniting the main burner on a propane-fired appliance. The burner is lit with an electric spark and the flame is monitored by an electronic circuit board. This ignition system is used in refrigerators, furnaces, and water heaters. There is now a version of stovetops that light the burners with a DSI ignition.
Ducted AC – Air conditioning supplied through a ducting system in the ceiling. This supplies cooling air at various vents located throughout the RV.
Ducted Heat – Warm air from the furnace supplied to various locations in the RV through a ducting system located in the floor. (similar to house heating systems)
Dump Station – A facility for dumping or emptying your black water and gray water holding tanks.
Dual Electrical System – RV equipped with lights, appliances that operate on 12-volt battery power when self-contained, and with a converter, on 110 AC current when in campgrounds or with an onboard generator.
Dually – A pickup truck, or light-duty tow vehicle, with four tires on one rear axle.
Equalizing Hitch – A hitch that utilizes spring bars that are placed under tension to distribute a portion of the trailer’s hitch weight to the tow vehicle’s front axle and the trailer’s axles. This hitch is also known as a weight distributing hitch
Fresh (Water) Tank – The gallons of freshwater that can be stored for later use.
Full Hookup – The ability to connect to all three of the campground’s facilities; electric, water, and sewer.