14
Brake Systems
BRAKE SYSTEM COMPONENTS
Tow Vehicle Battery.
The primary power source for the trailer braking system
is the tow vehicle battery. The connection is made at the
positive post of the battery, or at the tow vehicle starter
solenoid battery terminal.
Brake Controller
.
Electric trailer brakes are automatically applied by the
brake controller, which is usually mounted within easy
reach of the driver. Connect an electric brake controller to
the brakes with 12 gauge, stranded wire. Some controllers
are connected to the tow vehicle’s hydraulic brake system,
and are actuated when tow vehicle brakes are applied. Other
information about brake controllers:
§
Most experienced drivers prefer the trailer brakes to be
set to engage slightly before the tow vehicle brakes.
§
During rainy weather or slippery road conditions, if the
tow vehicle brakes rst, the trailer will have a tendency
to push the tow vehicle or possibly “jackknife”.
§
Lag time can be adjusted by turning the brake controller
knob. The new setting will be retained until a new
adjustment is made.
§
Brake controllers usually have a manual feature,
allowing the trailer brakes to be applied independently
of the tow vehicle brakes.
§
Consult instructions supplied with the controller for
further information.
WARNING: DO NOT INSTALL A FUSE IN THE CIRCUIT
BETWEEN THE TOW VEHICLE BATTERY AND AN
ELECTRIC OR ELECTRONIC BRAKE CONTROLLER.
A BLOWN FUSE WOULD CAUSE THE CONTROLLER
TO CEASE FUNCTIONING, CAUSING TRAILER
BRAKING LOSS WITH NO ADVANCE WARNING.
CIRCUIT PROTECTION SHOULD BE INSTALLED
PER THE BRAKE CONTROLLER MANUFACTURER’S
INSTRUCTIONS.
Connector Plug.
The 7-pin connector on the trailer hitch transfers 12 Volt
DC electrical power from the tow vehicle battery to the
trailer brakes, exterior lighting system, and battery. After
hitch connections have been made the 7-pin connector
must be longer than the extended safety chains. extended
connector life:
§
Keep the plug clean, tight and protected from the
elements.
§
Inspect the plug carefully every time you hitch up.
§
Always connect a 10 gauge, stranded, insulated copper
“charge line” from the alternator on the tow vehicle to
the trailer’s 12-volt connector. The “charge line” will
keep the trailer battery charged while traveling.
§
A 30-amp circuit protector should be installed near the
alternator connection.
Breakaway Switch.
This device is a vital component of the trailer’s braking
system. The breakaway switch is located on the trailer
tongue. The basic concept of a breakaway switch is:
A steel cable (lanyard) is fastened to the switch,
1.
which should connect to the frame of the tow
vehicle.
When connected to the tow vehicle frame, the
2.
lanyard cable should be longer than the extended
safety chains.
It automatically applies the trailer brakes if the
3.
tow vehicle and trailer become uncoupled while in
motion.
The breakaway switch operates when a pull pin
4.
linked by a cable to the tow vehicle separates from
the switch.
As the switch closes, the trailer battery supplies
5.
power to apply the brakes.
The steel lanyard must be anchored to the tow
6.
vehicle when the trailer is hitched. Secure this cable
loop to the permanent frame of the tow vehicle, or
a non-removable part of the hitch.
Do not fasten the breakaway switch lanyard to the
7.
hitch ball or any other removable part of the hitch.
Remove the pull pin every three months and lubricate it
with light oil. Before reinserting the pin, spray the inside
of the switch with an electrical contact cleaner to prevent
corrosion. Test breakaway switch operation before each
trip, as follows:
Hitch the trailer to the tow vehicle.
1.
Pull out the pull pin.
2.
Test the breaker by attempting to drive away. If the
3.
breakaway switch is functioning properly, the trailer
brakes will be activated.
If the brakes are not activated, check to make sure
4.
that the trailer battery is connected and fully charged,
and the trailer brakes are properly adjusted.
If the trailer brakes do not operate after making these
5.
checks, contact your dealer for repair.
Reinsert the pull pin before towing the trailer.
6.
WARNING:
DO NOT TOW A TRAILER WITH A
MALFUNCTIONING BREAKAWAY SWITCH.
DO NOT LEAVE THE PULL PIN OUT OF THE
BREAKAWAY SWITCH FOR MORE THAN A FEW
MINUTES, OR THE BATTERY WILL BE DRAINED.
DO NOT USE THE BREAKAWAY SWITCH FOR A
PARKING BRAKE.
