What was found
ADDENDUM TO SDR DATED 1-4-96. RT ENGINE STARTER MOTOR FIELD WINDINGS FAILED, APPARENTLY WHILE STARTER ENGAGED TO CRANK THE ENG RESULTING IN A SHORT-TO-GROUND OF STARTER POWER CIRCUIT. PILOT HAD NO INDICATIONS OF TROUBLE, AND ENG STARTED NORMALLY AND CONTINUED TO RUN NORMALLY DURING PRE-FLT RUN-UP. HEAT IN STARTER CIRCUIT CAUSED STARTER SOLENOID CONTACTS TO STICK CAUSING POWER TO CONTINUE TO FLOW TO STARTER MOTOR EVEN THOUGH STARTER SWITCH HAD BEEN RELEASED. THE SHORT-TO-GROUND INSIDE THE STARTER MOTOR DELETED ACFT BATTERY AND ALTERNATORS COULD NOT KEEP UP WITH THE LOAD AND ALL ACFT SYSTEMS DROPPED OFF-LINE. OCCURRED AT ROTATION ON T/O, & PILOT RETURNED TO AIRPORT. LANDED WITHOUT RADIO COMM.