# SDR 2018FA0000191

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 21, 2017
- Submitted: June 19, 2018
- Operation: General aviation
- Aircraft: [N681MA](https://openairdocs.org/aircraft/N681MA), registered now
- Make and model: Cessna 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (OpenAirDocs)
- Aircraft serial: 8203
- Aircraft time: 7,745 hours
- Engine: Lyc IO360L2A
- Engine time: 7,097 hours
- System (JASC): [7930 · Engine Oil Indicating System](https://openairdocs.org/jasc/7930)
- Part: Pressure Switch
- Part number: 83278
- Condition: Failed
- Location: Oil
- Part time: 66 hours
- Stage of operation: CR
- How discovered: O
- Nature of condition: N
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2018FA0000191

## Discrepancy

NEW OIL PRESSURE SWITCH CAUSED ERRONEOUS LOW OIL PRESSURE ANNUNCIATION AND HOUR METER FAILURE.  REPLACING THE SWITCH WITH A UNIT OF A DIFFERENT LOT NUMBER RESOLVED THE PROBLEM WITH NO DEFECTS TO EITHER THE OIL PRESSURE INDICATION AND RESTORED THE FUNCTION OF THE HOUR METER.

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