What was found
LEFT INTAKE HEAT INOP, LIGHT CAME ON WHEN ENTERING PRECIP. RETUNRED TO DTW. MAINTENANCE REPLACED LEFT DE-ICE MODULE, CLEANED ALL CANNON PLUGS AND TEST PLUG. GROUND RAN AIRCRAFT IAW SF340MM POM, ALL TORQUE SETTINGS AND ANTI-ICE CONFIGURATIONS TRIED. OPS CHECK GOOD. TEST FLIGHT SATISFACTORY. ALL CHECKS GOOD.