As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GTF FLIGHT NR 2411: WINDSHIELD CONTROL CAUTION LIGHT ILLUMINATED WHEN WINDSHIELD HEAT WAS SELECTED ON. FLIGHT DIVERTED BACK TO GTF. MAINTENANCE CLEARED CAUTION IAW Q400 FIM TASK 30-40-00-810-805. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.