Narrative:

Upon departing cvg the left main gear amber light remained illuminated with all other lights out after gear selected up. Gear recycled as per manual with no change in status. Selected alternate extension as per manual, winched gear and received 5 green lights, 2 red lights and left amber light still on. No further winching attempted as per pilot's manual. Landing could not be accomplished at cvg due to runway closures (disabled aircraft). Proceeded to sdf and made an uneventful approach and landing (WX VFR). Left main door did strike the runway with very minor damage. My initial inclination was that we had an indication problem because the red light should have accompanied the amber indication. However, I couldn't rule out the possibility of a malfunctioning red light. I therefore performed the procedures for the 'worse case' situation and lowered the gear manually and winched the doors. There was some accumulation of snow/slush on the runway which could have caused an indication problem.

Related reports:

Google
 

Original NASA ASRS Text

Title: ACR MLG GEAR UNSAFE LIGHT ON DEP DIVERTED TO ALT ARPT DUE TO CLOSED RWY AT DEP STATION AND MANUALLY EXTENDED GEAR.

Narrative: UPON DEPARTING CVG THE LEFT MAIN GEAR AMBER LIGHT REMAINED ILLUMINATED WITH ALL OTHER LIGHTS OUT AFTER GEAR SELECTED UP. GEAR RECYCLED AS PER MANUAL WITH NO CHANGE IN STATUS. SELECTED ALTERNATE EXTENSION AS PER MANUAL, WINCHED GEAR AND RECEIVED 5 GREEN LIGHTS, 2 RED LIGHTS AND LEFT AMBER LIGHT STILL ON. NO FURTHER WINCHING ATTEMPTED AS PER PLT'S MANUAL. LNDG COULD NOT BE ACCOMPLISHED AT CVG DUE TO RWY CLOSURES (DISABLED ACFT). PROCEEDED TO SDF AND MADE AN UNEVENTFUL APCH AND LNDG (WX VFR). LEFT MAIN DOOR DID STRIKE THE RWY WITH VERY MINOR DAMAGE. MY INITIAL INCLINATION WAS THAT WE HAD AN INDICATION PROB BECAUSE THE RED LIGHT SHOULD HAVE ACCOMPANIED THE AMBER INDICATION. HOWEVER, I COULDN'T RULE OUT THE POSSIBILITY OF A MALFUNCTIONING RED LIGHT. I THEREFORE PERFORMED THE PROCS FOR THE 'WORSE CASE' SITUATION AND LOWERED THE GEAR MANUALLY AND WINCHED THE DOORS. THERE WAS SOME ACCUMULATION OF SNOW/SLUSH ON THE RWY WHICH COULD HAVE CAUSED AN INDICATION PROB.

Data retrieved from NASA's ASRS site as of August 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.