Narrative:

Aircraft called from runway with 'B' flight control 'low pressure' light on P5-3 illuminated. Pressure and quantity indication normal. Came back to gate. Not in stock/ZZZ XXX-XXXX, so I installed the alternate YYY-YYYY, operations ok'd. Coordination, sent him on his way to ZZZ1 while doing paperwork review, I realized that this aircraft has the 'psep' modification, adding the 'standby pump on' light to the P5-3 panel. The panel I robbed from, does not have this light. I notified maintenance control immediately and arranged for the correct si panel to be installed at its first stop in ZZZ1.

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Original NASA ASRS Text

Title: A B737-300 WAS DISPATCHED IN NON COMPLIANCE WITH THE INCORRECT P5-3 OVERHEAD HYD FLT CTL PANEL INSTALLED.

Narrative: ACFT CALLED FROM RWY WITH 'B' FLT CTL 'LOW PRESSURE' LIGHT ON P5-3 ILLUMINATED. PRESSURE AND QUANTITY INDICATION NORMAL. CAME BACK TO GATE. NOT IN STOCK/ZZZ XXX-XXXX, SO I INSTALLED THE ALTERNATE YYY-YYYY, OPS OK'D. COORD, SENT HIM ON HIS WAY TO ZZZ1 WHILE DOING PAPERWORK REVIEW, I REALIZED THAT THIS ACFT HAS THE 'PSEP' MODIFICATION, ADDING THE 'STANDBY PUMP ON' LIGHT TO THE P5-3 PANEL. THE PANEL I ROBBED FROM, DOES NOT HAVE THIS LIGHT. I NOTIFIED MAINT CTL IMMEDIATELY AND ARRANGED FOR THE CORRECT SI PANEL TO BE INSTALLED AT ITS FIRST STOP IN ZZZ1.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.