B737-300 MECH SWAPPED AN INOP FUEL GAUGE INTO #2 POS WHILE CORRECTING A PROB WITH #1 SYS.

Narrative

FUEL GAUGE PROB. WE REQUESTED MDW MAINT ASSISTANCE IN DEFERRING OR REPAIRING AN INOP #1 FUEL QUANTITY GAUGE. THE MECH WHO WAS GIVEN THE TASK OF REPAIRING OUR GAUGE PROB MUST HAVE SWITCHED THE GAUGES WHILE DOING THE INITIAL TROUBLESHOOTING. AFTER HE HAD REPLACED THE GAUGE AND COMPLETED THE PAPERWORK WE CONTINUED OUR FLT SEQUENCE TO BDL. ON CLBOUT; I NOTICED THAT OUR #2 FUEL GAUGE WAS STILL INDICATING THE SAME FUEL QUANTITY THAT WE HAD PRIOR TO DEP. WE ULTIMATELY DETERMINED THAT THE MECH HAD SWITCHED FUEL GAUGES AND THEN LEFT THE INOP GAUGE IN THE #2 WING TANK POS INSTEAD OF REPLACING IT. THE ACFT HAD BEEN REFUELED PRIOR TO THE MECH WORKING ON THE GAUGES AND I WAS CONFIDENT THAT WE INDEED HAD THE REQUIRED FUEL IN THE #2 TANK TO COMPLETE THE FLT TO BDL. WE CONSULTED WITH DISPATCH AND MAINT CTL AND THEY AGREED THAT WE COULD CONTINUE TO OUR DEST. SUPPLEMENTAL INFO FROM ACN 559145: APPARENTLY; THE MAINT TECHNICIAN SWITCHED THE #1 GAUGE TO THE #2 POS DURING TROUBLESHOOTING THE SYS. AFTER LOGBOOK PAPERWORK WAS COMPUTED; FLT CONTINUED MDW TO BDL. ON CLBOUT; #2 FUEL QUANTITY INDICATOR SHOWED NO XFER INITIALLY. DURING DISCUSSIONS WITH DISPATCH AND MAINT; #2 INDICATOR GAVE SECOND UNRELIABLE INDICATIONS. THESE INDICATIONS WERE SIMILAR TO THE ONES THAT OCCURRED WITH #1 INDICATOR WHICH WAS NOW OPERATING PROPERLY. ACFT HAD BEEN REFUELED AT MDW PRIOR TO MAINT TECHNICIAN WORKING ON GAUGES. CREW WAS CONFIDENT THAT REQUIRED FUEL WAS ABOARD ACFT TO COMPLETE FLT. AFTER CONSULTING DISPATCH AND MAINT; CREW AGREED THAT FLT COULD SAFELY CONTINUE TO DEST.