Viper alarm on the fritz.

Someone tried to steal my buddy's RX-7 which set off the Viper alarm that a previous owner had installed. He turned the alarm off, drove the car home and there it sits. Put the key in and everything comes on but the ignition is dead. He's replaced the starter and all that to no avail which leads him to believe it's the alarm killing the ignition. Anyone know how to reset one of these things? Anyone have anything I can look into to try to help him out? Any help appreciated.