As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT ENGINE INTAKE LIGHT CYCLED ON AND OFF NUMEROUS TIMES; RAN QRH--NO CHANGES. IT CYCLED FOR THE REMAINDER OF FLIGHT. AIR RETURN TO DTW. MAINTENANCE FOUND NR 3 THERMOSTAT ON LOWER DUCT OPEN--SWAPPED TO NR 4 POSITION. COMPLETED OP'S CK'S IAW AMM. ALL CHECKS GOOD. SEE 409 NR 131454 FOR DETAILS.