As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS HAVING A HEATING PROBLEM. (COULD NOT GET HEAT INTO CABIN) WHILE TROUBLESHOOTING. MAINTENANCE FOUND A CLAMP LAYING ON THE REAR COMPARTMENT FLOOR BROKEN. THE CLAMP CAME FROM THE FWD SIDE OF THE RAM-AIR PRECOOLER, HOWEVER, THE HEATING PROBLEM WAS NOT CAUSED BY THE BROKEN CLAMP. MAINTENANCE FOUND A BAD RAM AIR MODULATING VALVE.