Methods and apparatus are provided for a functional high-voltage interlock system. The apparatus includes an enclosure, a high-voltage terminal, a low-voltage circuit, and a control circuit. The enclosure includes an access point that may be breached. The high-voltage terminal is disposed at least partially within the enclosure, is accessible by breaching the high-voltage access point, and is configured to be energized from a high-voltage electrical power source. The low-voltage circuit is disposed within the enclosure, and is coupled to selectively receive a low-voltage electrical signal. The control circuit is coupled to, and is configured to supply the low-voltage electrical signal to, the low-voltage circuit only when the high-voltage access point is not breached. The control circuit implements a first function and a disparate second function. The first function determines whether the access point is breached and, if so, prevents the high-voltage terminal from being energized from the high-voltage electrical source.