As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FWD CAB TEMP CONTROLLER WILL NOT HOLD SELECTED TEMP. IT WILL SPIKE HOT OR COLD. HAD TO CONTINUOUSLY MONITOR AND ADJUST. SUPPLY DUCT TEMP RANGED BETWEEN 8C - 45C. GROUNDED - YES. PERFORMED BITE CK OF BOTH CABIN TEMP CONTROLLERS WITH NO FAULTS LOGGED. ACCOMPLISHED FIM TASK 21-61 TASK 864 INITIAL EVAL. WITH TEMP INDICATIONS NORMAL.