An apparatus and method for equipping a locomotive with a modular radio communication system capable of being expanded to incorporate future improvements in radio and data communication electronics. The modular radio communication system provides for the installation of a standardized mounting plate and housing onto the rooftop of the locomotive to reduce the need to make extensive mechanical and electrical modifications to the locomotive when the radio communications system is updated. Sunscreens and vent openings in the standard mounting plate and housing work to reduce the temperature of the internal components of the modular radio communications system.