Electric Brake Engagement

I have a travel trailer with electric brakes. The problem we are having is with the brakes. The brakes will engage when pulling it even though we do not have the brakes hooked up in the plug-in on the back of the truck. We unhooked the battery on the trailer and currently do not have this problem but it is not safe to tow the trailer without the brakes. What could be the problem?
Tammy, (Laure, TX)

Tammy, all travel trailers equipped with electric brakes must also be outfitted with a device called an emergency break-away switch. The purpose of this switch is to engage the trailer's electric brakes if the tow vehicle and trailer should ever become uncoupled while traveling down the highway. The power for this switch comes from the trailer battery which is why your symptoms disappear when the battery is disconnected.

The switch should be located at or near the tongue of the trailer and consist of box-like device with a pin fully inserted in the switch with a long cable that attaches to the hitch of the tow vehicle. When the pin is pulled, (picture a hand grenade), the switch closes and voltage is allowed to pass to the electric brakes on the trailer. Either your pin has been pulled out or the switch is simply faulty.

Break-away switches are relatively inexpensive and available at any RV accessory store. They should be cleaned and tested from time to time. If the pin and the cable attaching it are missing, a complete new switch should be installed. To test a break-away switch, jack up one side of the trailer and have a partner spin the tires on that side. The tow vehicle does not need to be connected for this test; a healthy trailer battery does, however. While they are spinning, pull the pin from the break-away switch; the brakes should immediately lock up. If they do not, there is an open in that circuit and further troubleshooting is in order. Jack up the opposite side and try the same test.