What was found
DURING CLIMBOUT, THE LEFT ICE PROTECTION TEMPERATURE HIGH LIGHT ILLUMINATED ONCE THE ANTI-ICE SWITCH WAS TURNED TO THE OFF POSITION. FLIGHT CREW CONSULTED WITH MAINTENEANCE CONTROL, RETURNED TO ORIGINATION AND LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED THE THERMO-ELECTRIC CONTROL UNIT, THE LEFT HIGH TEMPERATURE SENSOR, AND THE LEFT ANTICIPATOR AND THERMOSTAT, OPERATIONAL CHECK OK.