As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHORTLY AFTER TAKEOFF TRIM AIR OFF LIGHT ILLUMINATED COURIER SUPPLY TEMP INCREASED TO 215 DEG IT THEN DROPPED AND TRIM AIR OFF LIGHT EXTINGUISHED. SUPPLY TEMP ROSE AGAIN, CYCLED REPEATED MULTIPLE TIMES. RETURNED TO BASE. BOTH TRIM AIR PRESSURE REGULATOR VALVES INOP. TRIM AIR SWITCH MUST BE SELECTED.