What was found
AFTER GEAR RETRACTION, LEFT LOOP A GREEN LIGHT REMAINED ILLUMINATED. ATTEMPTED TO CYCLE GEAR AND GEAR WOULD NOT EXTEND. USED QRH GEAR ELECTRICAL OVERRIDE PROCEDURE TO EXTEND GEAR. RETURNED TO MFR. CLEANED AND ADJUSTED LOOSE PROXIMITY SWITCH, SWUNG GEAR AND OPS CHECK GOOD IAW 32-00-00.