What is the primary function of a break away switch?

The primary function of a breakaway switch is to apply electric trailer brakes in the event the tow vehicle becomes separated from the trailer. This safety feature is crucial for preventing serious accidents and damage when a trailer disconnects from its towing vehicle while on the road.

When the breakaway switch is activated—typically by a pin that is pulled out when the trailer separates—it completes an electrical circuit that engages the trailer’s brakes. This helps to bring the trailer to a stop safely and minimizes the risk of the trailer rolling uncontrolled. The effectiveness of a breakaway system is essential for maintaining safety standards in towing operations and is usually mandated by regulations for trailers that exceed a certain weight.

The other options describe functions that do not align with the specified role of a breakaway switch. Turning off coach batteries or applying pressure to the hitch are not related to the emergency functionality intended by the breakaway switch. Additionally, while applying brakes on the tow vehicle could be a safety feature, it is not the role of the breakaway switch, which focuses specifically on the trailer's braking system.