The Innovative Controls Inc Door Monitor System is comprised of a cab display and door input module. The Door Monitor System is used to display the status of crew cab doors, tool and SCBA bottle compartments, ladder and step position, and deck guns. The Door Input Module is housed in a standard waterproof automotive enclosure so it can be located any place convenient to the door proximity sensors. The Door Input Module interfaces with the Cab Display via a J1939 CAN Bus network to simplify installation. An optional parking brake input and alarm output can be used to sound a cab alarm when a door when the park brake is released.