What was found
FLT 647, RETURNED TO FIELD. ON CLIMB OUT, AP 1 ENGAGED FL 280, ACFT PITCHED DOWN, SAT & TAT SHOWED EXTREME NEG NUMBERS. DISENGAGED AP, LEVELED AT FL 320. SAT & TAT AMBER XX. DURING DESCENT, FO WOULDN`T FOLLOW PROFILE AGAIN, EXTREME NEG SAT NOTED. CHECKED TAT 1 RESISTANCE, FOUND 553 OHMS, 80 DEG F. R & R TAT 1 IAW AMM, OPS CHECKED GOOD. CHECKED NEW TAT 1 RESISTANCE IAW CMM, FOUND 559 OHMS, 80 DEG F. CHECKED CONTINUITY FOR TAT PINS J & E TO ADIRU 1 PINS 8H & 8J, 1.2 OHMS. NO FAULTS. CHECKED CONTINUITY FROM JUNCTION 1513VC PIN 2 & 3 TO TAT 1 PINS J & E. .7 OHMS. NO FAULTS. WIGGLED WIRES, NO FINDINGS. WIRE INSP OK IAW AWM. MEGGED WIRES, NO FAULTS. R & R TAT 1 CONNECTOR IAW ESPM 20-44-10. CONNECTIONS OK.