What was found
DURING DESCENT THE AUTOPILOT DISCONNECT AURAL WARNING FAILED TO SOUND WHEN AUTOPILOT B WAS DISCONNECTED AT FO YOKE SWITCH. THE DISCONNECT LIGHT DID ILLUMINATE DURING DISCONNECT. SAME RESULT FOR AUTOPILOT A. SAME RESULT WHEN USING DISCONNECT SWITCH ON CAPTAINS YOKE. GROUNDED - YES. REF B737-900 SSM 31-51-11-102, B737-900 WDM 22-14-11-2, B737-900 AMM 22-11-34/401, AMM 31-51-04. CONFIRMED FAULT, ACCOMPLISHED CONTINUITY CHECK ON MCP CONNECTOR D299, PIN 48 TO CONNECTOR D940 PIN 4 ON AURAL WARNING MODULE. SHOWED OPEN. FOUND BROKEN WIRE AT PIN 4 OF CONNECTOR D940 TO AURAL WARNING MODULE. REPAIRED WIRE. AURAL WARNING MODULE OPS TEST NORMAL. REF AMM 22-11-34/401. ALL REQUIRED TESTS PASSED. THIS CLEARS MEL 22-2F, 22-99B.