# SDR ASAA2016122919203

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 29, 2016
- Submitted: January 4, 2017
- Operation: Air carrier
- Aircraft: [N588AS](https://openairdocs.org/aircraft/N588AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35685
- Aircraft time: 34,848 hours, 10,599 cycles
- System (JASC): [2697 · Fire Protection System Wiring](https://openairdocs.org/jasc/2697)
- Part: Wire Harness
- Part number: 3250275060
- Condition: Failed
- Location: Nr 1 Engine
- Stage of operation: NR
- How discovered: O
- Nature of condition: N
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2016122919203

## Discrepancy

NR 1 ENGINE A LOOP OF FIRE DETECTION SYSTEM INOP. GROUNDED - YES. ENGINE/APU FIRE BITE SHOWS WIRING OPEN OR DETECTORS FAULT. FAULT LIGHT ILLUMINATED WHEN SWITCHED TO A LOOP. AFTER OPENING INBOARD TR FAULT LIGHT EXTINGUISHED. DISCONNECTED ALL A LOOP DETECTORS, GVI ON ALL CONNECTION, NO DEFECTS NOTED. RESISTANCE CHECKED ON ALL DETECTORS - WITHIN LIMITS, NO FLUCTUATION DURING TAPPING. SECURED ALL WIRE HARNESS FOR DETECTORS. DURING CONTINUITY CHECKS FOR CORE LOOPS, OPEN LINE WAS OBSERVED WHEN FLEXING MW0325. REMOVED & REPLACED MW0325 ENGINE CORE FIRE HARNESS, REF FIM 26-10 TASK 08 & WDM 26-11-11, ENGINE FIRE TEST NORMAL.

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