Hitching Systems
The trailer towing industry has developed
a classification system that differentiates hitches according
to the amount of weight they can tow. This system addresses
tongue weight and total weight. Keep in mind that within each
classification are numerous hitches made by a variety of manufacturers.
The three most common types of hitches are
the weight-carrying hitch, the weight-distributing (or load
equalizer) hitch, and the fifth-wheel hitch, or gooseneck.
Weight-carrying hitches are designed to carry all of the trailer’s
tongue weight. Weight-distributing hitches are used with a
receiver hitch and special parts that distribute the tongue
weight among all tow vehicle and trailer axles.
Fifth-wheel hitches are designed for mounting the
trailer connection point in the middle of the truck bed.
fifth-wheel
hitches
When purchasing a hitch, use the recommendations
of the manufacturer of the tow vehicle and trailer based on
the type and weight of the trailer. Make sure the hitch has
provisions for the connection of
safety chains, which are required by most states.
When connected, safety chains should have some slack to permit
sharp turns but should not drag on the road. In addition,
they should cross under the trailer tongue to help prevent
the tongue from dropping to the road in the event the trailer
separates from the tow vehicle.
safety chains
Braking Systems
The selection of a brake system also will
depend on your tow vehicle and the type and fully loaded weight
of your trailer. For a trailer with a loaded weight of more
than 1,500 pounds, many states require a separate braking
system and a breakaway switch, located on the tongue of the
trailer, to activate the trailer brakes in the event the trailer
separates from the tow vehicle. There are two basic types
of brake systems designed to activate the brakes on a trailer:
- Electronically controlled brakes usually
provide automatic and manual control for trailer brakes.
They require that the tow vehicle be equipped with a controlling
device and additional wiring for electrical power. These
brakes typically have a control box installed within reach
of the driver and can be manually or automatically applied.
The control box may require adjustment or “tuning in” for
variations in trailer load.
- Surge brakes are independent hydraulic
brakes activated by a master cylinder at the junction of
the hitch and trailer tongue. These brakes are not controlled
by the hydraulic fluid in the brake system of the tow vehicle.
Note: The hydraulic system of the tow vehicle should never
be directly connected to the hydraulic system of the trailer.
These systems are self-compensating and do not require adjustment
for variation in trailer load.
Follow the tow vehicle manufacturer’s recommendations
for brake selection. Some states require braking systems on
all axles of the trailer. So, check your state’s requirements
by contacting the motor vehicle administration.
Wiring Systems
Federal law requires trailers to have taillights,
brake lights, side marker lights, turn signals, and side and
rear reflectors. Some trailers also have backup lights. To
provide power to these lights, a four-way (or more) connector
is hooked into the tow vehicle’s electrical system. Many tow
vehicle manufacturers offer a 7-way
connector that may include an electric brake signal,
power supply, and backup lights, in addition to the typical
four functions. Note: You must ensure that the signals on
the electrical connector of the tow vehicle match the electrical
connector of the trailer.
connector
Because the wiring systems of many tow vehicles
use separate wires for turn signals and stop lights, you may
need to purchase a taillight converter. This converter will
combine these wires so that they can be connected to the trailer
lighting system. Most factory-installed towing packages include
a trailer wire harness that will perform this function if
required. If you tow more than one type of trailer, you also
may need to purchase an adapter to accommodate differences
in the wiring systems.
