As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ANTI-ICE DUCT MESSAGE DURING CLIMBOUT OF RDU. MSG AND AURAL ON THRU FL180 WITH ANTI-ICE IN OFF MSG AND AURAL INTERMITTENT BACK TO RDU. AUTO-ICE SYNOPTIC PAGE SHOWED RED LEADING EDGE ON LEFT WING. REMOVED AND REPLACED LEFT WING 21 THERMAL SWITCHES AND OPS CK GOOD IAW C--65 AMM 36-21-07, OPS CK GOOD.