An switching interface is provided for use on a vehicle. In an exemplary embodiment the switching interface comprises a receiver and a switch assembly. The receiver may include an input node; a regulated power supply electrically couple to the input node; and an analog-to-digital (A/D) converter configured to measure a voltage potential between the input node and the receiver ground. The switch assembly may include a first resistor electrically coupled to the receiver input node, the first resistor having a first resistive value; a first switch electrically coupled between the first resistor and a switch assembly ground; a second resistor electrically coupled to the first resistor and the first switch, the second resistor having a second resistive value; and a second switch coupled between the second resistor and the switch assembly ground. The first and second resistive values may be selected such that the switch assembly has a separate switch assembly state for each switch with an associated voltage potential measured between the input node and ground for each of the switch assembly states.