What was found
AFTER DEPARTURE, AN ODOR OF A WIRE BURNING AND SHORTLY AFTER, SMOKE APPEARED TO COME FROM BEHIND THE COCKPIT. TURNED THE AIR CONDITIONING OFF AND THE SMOKE STOPPED, TURNED AROUND AND LANDED BACK AT DEPARTURE. UNABLE TO DUPLICATED, IDENTIFIED THE BLOWER AS INOPERATIVE, BLOWER WAS REPAIRED AND AIRCRAFT WAS RETURNED TO SERVICE WITH NO FURTHER ISSUES.