As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NUMBER 1 ENGINE B FIRE DETECTION LOOP DOES NOT TEST PROPERLY. GROUNDED - YES. PERFORMED B737-800 FIM 26-10 TASK 801 BITE SHOWS NO FAULTS. TEST PERFORMS NORMALLY WITH NO FAULTS. DUE TO HISTORY PERFORMED VISUAL CHECK OF ENG 1 FIRE DETECTION WIRE HARNESS. FOUND HARNESS MW0316 FAN UPPER RIGHT AND LOWER LEFT TERMINAL DAMAGED. REPLACED HARNESS REF B737-800 WDM 26-11-11 PAGE 1 AND B737-800 AMM 26-10-00-710-801 ALL TEST PASS.