What was found
DURING CLIMB OUT, AIR CONDITIONING SELECTED ON AND A STRONG ODOR OF BURING FILLED THE COCKPIT. ACFT RETURNED AND LANDED SAFELY. DURING INITIAL INSPECTION, A COCKPIT TEMP SENSOR BLOWER POWER WIRE WAS FOUND SHORTED TO A NEARBY SHIELDED WIRE AND THE CIRCUIT BREAKER WAS TRIPPED. WIRE HAD A BARE PORTION NEAR A CONNECTOR AND REPAIRED THE WIRE AND COCKPIT TEMP SENSOR UNIT REPLACED FOR A BURNED OUT MOTOR. ADDITIONALLY, AIR CONDITIONING CIRCUIT BREAKER WAS REPLACED AS A PRECAUTION SINCE IT WAS TRIPPED. ACFT WAS GROUND RUN AND CIRCUIT BREAKER NO LONGER TRIPS, THE AIR CONDTIONING FAIL ANNUNCIATOR LIGHT ILLUMINATED. ACM IS IN THE AFT FUSELAGE AND THE BLEED AIR OVER TEMP SWITCH WAS REPLACED. IT WAS NOT ELECTRICALLY CLOSING UNTIL 516 DEGREES F, AND THE LIMIT IS 400 F. PERFORMED ENGINE RUNS AGAIN AND NO FAILS OCCURRED.