What was found
PIE - FLT 220 - DEPARTING EWR, UPON GEAR RETRACTION, 'LEFT GEAR UNSAFE' AND 'GEAR DOOR OPEN' LIGHTS REMAINTED ILLUMINATED. REFERRED TO ABNORMALS CHECK LIST 'RED LIGHT ON WITH GEAR HANDLE UP'. CYCLED L/G, LIGHTS EXTINGUISHED AND UPLOCK CHECKED GOOD. CONTINUED FLT. INSPECT MLG LEFT DOOR LATCH PER MM 32-31-4. ALL MEASUREMENTS FOR CATCH ASSY GOOD. FOUND TRACES OF DIRT IN UPLOCK SWITCH CANNON PLUG. CLEANED CANNON PLUG THOROUGHLY AND RE-INSTALLED. CLEANED CANNON PLUG FOR GEAR DOOR SW LIGHTS. OPS CK NORM PER 32-60-1. R/R'D LEFT MLG UPLIMIT SW IAW 32-60-1. UNIT OPS CHECK GOOD. (M)