It is a Federal requirement that any trailer which must be fitted with brakes must also be fitted with a breakaway device, sometimes called an emergency brake. According to the California Department of Motor Vehicles, this applies to "Any trailer having a gross weight of 1500 lbs. or more and manufactured after December 31, 1955." In the electrically-operated systems usually fitted to travel trailers an emergency backup battery is fitted to the trailer, along with a breakaway switch and a pull-pin attached to a cable. The battery is charged by a charger powered from the tow vehicle. The cable is secured to the tow vehicle, and if the trailer is separated from the tow vehicle while under way the cable pulls the pin from the switch, then the switch uses the battery's power to fully deploy all the brakes.
Things You'll Need
- Emergency brake kit
- Craft knife
- Wire strippers
- Soldering kit
- Shrink-wrap insulation kit
Mount the breakaway switch on the tongue of the trailer, in a location where the pin cable can be strung without obstruction to a sturdy hanger on the tow vehicle. Breakaway switches typically have one or two tabs on their case through which self-tapping screws can be driven to fix them in place.
Mount the battery box on the tongue of the trailer, in a location where it is protected from accidental damage. Battery boxes typically have four holes in the base to pass fasteners through; align the box on the tongue so that at least two of the holes are over a frame rail, then use a permanent marker pen to mark the location of the holes on the tongue. Remove the battery box, drill pilot holes in the center of the marks, reinstate the battery box and drive the provided fasteners through the battery box holes into the pilot holes.
Consult the manufacturer's instructions delivered with the emergency brake kit to determine the correct battery size; it must be 12-volt to deploy 12-volt electric brakes. Install the battery in the battery box and tighten down the securing strap if one is fitted.
Attach the integral battery charger to the battery, and to the 12-volt hot wire in the trailer's preexisting harness. Find a place in the harness where the outer sleeve is separated from the seven wires, close to the hitch if necessary, and separate the black wire. Use a craft knife to strip away half an inch of the color-coded insulation, and use wire strippers to strip half an inch of insulation from the battery charger wire. Twist the bared battery charger wire around the bared hot wire in the harness, solder the join, then insulate the join with a shrink-wrap kit.
Attach one of the wires from the breakaway switch to the positive terminal of the battery using the supplied cable. Either of the two wires can be used.
Connect the other of the breakaway switch wires to the blue wire in the trailer's seven-conductor harness; the blue wire runs to the electric brakes. Find a place in the harness where the outer sleeve is separated from the seven wires, close to the hitch if necessary, and separate the blue wire. Use a craft knife to strip away half an inch of the color-coded insulation, and use wire strippers to strip half an inch of insulation from the breakaway switch wire. Twist the bared breakaway switch wire around the bared brake wire in the harness, solder the join, then insulate the join with a shrink-wrap kit.
Connect the negative terminal of the battery to ground using the supplied black color-coded cable. Travel trailer tongues usually have many screws and nuts driven into them; repurpose one of these for the ground connection, ensuring the contact faces are clean and flat. Install the lid of the battery box.
Insert the pin into the breakaway switch, then hang the loop at the other end of the pin's cable over a strong hitch on the tow vehicle such as the tow-ball or a towing hook. The run of the cable must be unobstructed, long enough to allow full movement of the tongue yet not so long it contacts the ground.
Follow the manufacturer's instructions to test the breakaway installation before using the trailer on the highway for the first time.
Tips & Warnings
- A travel trailer emergency brake kit, properly called an emergency breakaway kit, is sold complete with all the components except the battery.
- If it is necessary to extend the wire used to connect the breakaway switch to the blue wire in the preexisting harness, or the wire used to connect the battery charger built into the battery box, use no less than 14-gauge wire.
- Make testing the charge of the breakaway battery part of your hook-up procedure every time you ready the travel trailer for use.
- Photo Credit camping,trailer image by Greg Pickens from Fotolia.com
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