What was found
WITH THE W/S BLEED ANTI ICE ON LOW (APPROX 3-5 MINUTES AFTER BEING SWITCHED ON) THE W/S O'HEAT ILLUMINATED WITH SMOKE/HAZE IN THE COCKPIT AND CABIN ALONG WITH STRONG BURNING ODOR. VERIFIED RIGGING AND OPERATION OF W/S BLEED AIR VALVES, FOUND GOOD. VERIFIED OPERATION OF W/S BLEED AIR SHUTOFF/REGULATING VALVE, FOUND GOOD. VERIFIED TEMP SENSORS X-25,X-26, AND W/S O' HEAT SENSOR FOUND GOOD. VERIFIED 5 PSI SWITCH . FOUND GOOD. VERIFIED INPUT SIGNALS TO ANTI-ICE TEMP CONTROLLER FOUND GOOD. VERIFIED OPERATION OF TEMP CONTROLLER. FOUND CONTROLLER FAILED. OLD P/N: 9912085-6. OLD S/N: 3AN12. NEW P/N: 9912085-6. NEW S/N: 2BC44.