As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NOTICED ELECTRIC BURNING ODOR IN AIRPLANE WHILE ON GROUND WITH GPU CONNECTED, AIR CONDITIONING ON, AND BOTH FANS OPERATING. NOTICED SMOKE COMING FROM AIR CONDITIONG EXHAUST AND HYD DRAIN. GPU POWER WAS REMOVED FROM AIRPLANE. WHEN ACCESSING BATTERY TO DISCONNECT, HEAVY SMOKE WAS NOTED COMING FROM AFT COMPARTMENT. FOUND A/C MOTOR ON, REMOVED MOTOR AND INSTALLED O/H MOTOR AND NEW RECEIVER DRYER IAW MM 21-52-00. OPS CHECKED GOOD.