What was found
(CAN) WHILE PERFORMING MAINTENANCE, GROUND POWER WAS USED FOR TESTING. SMOKE WAS OBSERVED EXITING THE TOP OF THE RIGHT HAND ENGINE COWL. ELECTRICAL POWER WAS SHUT OFF. INVESTIGATION FOUND SMOKE COMING FROM THE AMBIENT AIR SHUTOFF VALVE SOLENOID, LOCATED INLINE BETWEEN THE PNEUMOSTAT AND THE BUTTERFLY AIR VALVE OF THE RIGHT SIDE FLO-PACK ASSEMBLY. THE SOLENOID IS POWERED TO CLOSE. IT IS NORMALLY OPEN AND IS THEREFORE POWERED UP WHILE THE AIRCRAFT IS ON THE GROUND WITH POWER TO THE BUS.