As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 3644 DURING TAXI THE CREW REPORTED A HOT ELECTRICAL WIRE INSULATION ODOR IN THE COCKPIT. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE ATTITUDE HEADING REFERENCE UNIT FAN IAW AMM 34-21-03. THE AIRCRAFT WAS RETURNED TO SERVICE.