What was found
PILOT REPORTED UPON COMPLETION OF PRE-FLIGHT CHECK, ACCELEROMETER SWITCH WOULD NOT TEST OR DISCONNECT AUTOPILOT AS REQUIRED BY POH INSTRUCTIONS. THE SYSTEM WAS FOUND TO DISCONNECT IN THE DOWN POSITION SOMETIMES, AND WOULD NOT DISCONNECT IN THE UP POSITION. THE SWITCH IS OF VERY POOR DESIGN AND CONSTRUCTION. INNER AND OUTER HOUSINGS ARE OF DISSIMILAR METAL AND DO NOT EXPAND AND CONTRACT AT THE SAME RATE NOT ALLOWING THE SWITCH TO MOVE AT DIFFERENT TEMPS. WHOLE SYSTEM IS OVER-ENGINEERED. ONE SIMPLE TSO TO REMOVE THE SWITCH FROM THE SYSTEM WOULD CURE THE PROBLEM. IF SWITCH IS USED FOR WHAT IT WAS DESIGNED, PILOT HAS ALREADY LOST CONTROL OF THE AIRCRAFT!!