What was found
CREW REPORTED, UNABLE TO DISCONNECT PITCH TRIM USING BOTH CONTROL WHEEL DISCONNECT BUTTONS. PROBLEM DETERMINED TO BE LOW VOLTAGE (22V) AT PIN -K-, CONNECTOR P312, THUS PREVENTING K1 TO REMAIN ENERGIZED ONCE PITCH/TRIM DISCONNECT SWITCH WAS RELEASED. CAUSE OF THE SNAG WAS WIRE C26D22 FOUND BROKEN BETWEEN PINS E & K ON CONNECTORS J393 & P312. PREVIOUS REPAIR INDICATED A POOR QUALITY SPLICE CAUSING WIRE TO CORRODED GIVING HIGH RESISTANCE WHICH LOWERED THE VOLTAGE AT PIN K. MAINTENANCE INSTALLED NEW SPLICE & SYSTEM WAS FUNCTION CHECKED SERVICEABLE. REF WIRING DIAGRAM MANUAL "ELECTRIC PITCH TRIM" 27-31-01-02, PAGE 1 OF 1.