# SDR CALA2026031614585

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 13, 2026
- Submitted: March 16, 2026
- Operation: Air carrier
- Aircraft: [N28478](https://openairdocs.org/aircraft/N28478), registered now
- Make and model: Boeing 737924ER
- Aircraft serial: 31649
- Aircraft time: 38,739 hours, 14,368 cycles
- System (JASC): [3397 · Light System Wiring](https://openairdocs.org/jasc/3397)
- Part: Wire
- Condition: Shorted
- Location: Zone 200
- Stage of operation: IN
- How discovered: C
- Nature of condition: L
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2026031614585

## Discrepancy

ALL OF FIRST-CLASS SEAT EMERGENCY LIGHTS INOPERATIVE.  R & R F2 5A FUSE IN FWD CHARGER.  FIRST CLASS SEAT EMER LIGHT ILLUMINATED FOR 1 SEC & WENT OUT. TRIED ANOTHER FUSE, FUSE BLEW AGAIN. IAW AMM 33-51-06-960-804.  SWAPPED AFT CHARGER WITH FWD CHARGER, SAME RESULTS. REPLACED AFT CHARGER FUSE & RETURNED TO NORMAL CONFIGURATION. AFT CHARGER OPS CHKD GOOD. WIRE SHORTING FWD, T/S REF WDM 33-51-21-7. TRIED TO ISOLATE SHORT, DISCONNECTED CONNECTOR D12052 & MEASURED RESISTANCE FROM M02816 PIN 12 TO GROUND, 0L,  NO SHORT TO GROUND IN RUN OF WIRE.  DISCONNECTED ALL LIGHTS FROM HARNESS IN ORDER TO ISOLATE, MEASURED DOWNSTREAM OF D12052 ACROSS PINS 2 TO 5. 0L, NO SHORT ACROSS POSITIVE & NEGATIVE. MEASURED POSITIVE SIDE TO GROUND, 40KOHMS, SHORT IS ON POSITIVE, T/S REF WDM 33-51-21-7.

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