As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED A RATTLING NOISE AND BURNING SMELL FROM THE REAR CABIN AIR CONDITIONER VENTS. LANDED WITHOUT INCIDENT AND CALLED MAINTENANCE. THE MECHANIC FOUND ONE OF THE DUAL SQUIRREL CAGE IMPELLORS HAD SHIFTED TO ONE SIDE AND WAS RUBBING ON THE FIBERGLASS BLOWER HOUSING. THE AFT BLOWER ASSEMBLY WAS CHANGED AND THE AIRCRAFT WAS RETURNED TO SERVICE.