As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MSO FLIGHT NR 2347: GEAR (ALL 3) FAILED TO RETRACT. LEFT MAIN LANDING GEAR DOOR LIGHT (AMBER) WOULD FLASH MOMENTARILY (EVERY 5 SECONDS OR SO) WHEN THE GEAR HANDLE WAS IN THE UP POSITION. RAN THE GEAR FAILURE CHECKLIST AND IT DID NOT SOLVE THE PROBLEM. AIRCRAFT RETURNED TO FIELD AND GATE. MAINTENANCE REMOVED AND REPLACED THE NLG ELECTRICAL HARNESS. CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.