What was found
EN ROUTE TO LAN TURNED INTAKE HEAT ON, WITHIN 5 SECONDS THE RIGHT INTAKE LIGHT ILLUMINATED, FOLLOWED QRH THEN LEFT INTAKE CAME ON. CREW EXITED ICING CONDITIONS AND RETURNED TO DTW. MAINTENANCE GROUND RAN ENGINE AND OPS CHECKED RIGHT AND LEFT INTAKE HEAT SYSTEMS, ALL CHECKS GOOD. NO DEFECTS NOTED. OPERATED SYSTEM SEVERAL TIMES, ALL INDICATIONS AND CHECKS ARE NORMAL. ALL WORK AND TROUBLE SHOOTING DONE IAW SAAB MM CHAP 30.