Description The towbar buzzer relay consists of two monitoring circuits, one circuit for each side of the vehicle. It is small and has been designed to be fitted behind interior at the rear of the vehicle. When a current passes through the buzzer relay from either trailer light flashing being detected the other monitoring circuit is activated to make a buzzing sound. The buzzer is fitted inline between the vehicles flasher circuits and the wires on the seven core cable carrying the current via the towbar socket to the trailer indicator lamps. The buzzer relay will only buzzer if a current is passing through it to the trailer lamps, meaning when no trailer is attached no buzz will be made, it will remain silent. If a trailer is connected and there is no buzz heard whilst the indicator lights are flashing, this warns the driver that the indicator on the towed unit has failed and not operating so can not be see by drivers behind. The reasons for the overwhelming popularity of the towbar buzzer relay other than it being a legal requirement, is the simplicity of the design, it is reliable, cheap and easy to fit. Audible Buzzer Towbar Relay Instructions
