# SDR 20010305CW004

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 12, 2001
- Submitted: March 5, 2001
- Operation: General aviation
- Aircraft: [N563SP](https://openairdocs.org/aircraft/N563SP), registered now
- Make and model: Cessna 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (OpenAirDocs)
- Aircraft serial: 172S8416
- System (JASC): [3110 · Instrument Panel](https://openairdocs.org/jasc/3110)
- Part: Potentiometer
- Condition: Misinstalled
- Location: Instrument Panel
- Stage of operation: IN
- How discovered: V
- Nature of condition: W
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/20010305CW004

## Discrepancy

REPORT THAT RADIO INDICATOR BACKLIGHTING AND RADIO CONTROL BACKLIGHTING HAD NOT WORKED SINCE DELIVERY OF AC.  TROUBLESHOOTING, FOUND THAT PIN 1 OF JC005 WAS AT GROUND POTENTIAL, PREVENTING DIMMER POTENTIOMETER FROM FUNCTIONING PROPERLY.  REMOVED WIRE FROM CIRCUIT, WIRE THAT HOOKS INTO WARNING / CAUTION ANNUNCIATOR.  RADIO LIGHTING WORKED CORRECTLY.  THE WAY SWITCH WAS INTERGRATED INTO SYSTEM WAS CAUSING HARD GROUND CONDITION.

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