As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK, DECLARED EMERGENCY EQUIPMENT COOLING OFF LIGHT ILLUMINATED INFLIGHT WITH SWITCH IN NORMAL AND ELECTRICAL BURNING ODOR NOTICED IN COCKPIT. LIGHT REMAINED ON WHEN SWITCH MOVED TO ALTERNATE. R & R AUTOMATIC FLOW CONTROL VALVE.