What was found
FLIGHT CREW REPORTED THAT STALL WARNING CAME ON IN-FLIGHT AND REMAINED ON. MAINTENANCE CREW REPLACED INBOARD STALL WARNING SWITCH (LIFT DETECTOR) DUE TO AN INTERNAL SHORT AND AIRCRAFT WAS RELEASED AFTER A SUCCESSFUL TEST FLIGHT. THIS OPERATOR HAS FOUND THIS STALL WARNING SWITCH TO BE SUSCEPTIBLE TO FAILURE ESPECIALLY AFTER PREVIOUS REPAIR. REMOVED SWITCH HAD 570.4 HOURS SINCE PREVIOUS REPAIR BY SAFE FLIGHT. IT IS SUSPECTED THAT MOISTURE CAUSES PREMATURE FAILURES.