What was found
(CAN) DURING DEPARTURE OF THE ACFT FROM MAIN BASE, THE PILOTS OF THE B300 ACFT RETURNED REPORTING ENVIRONMENTAL FUMES WERE PRESENT IN THE CABIN. MX INITIATED TROUBLESHOOTING & INSPECTION OF THE ENVIRONMENTAL SYSTEM. THEY REPLACED ENVIRONMENTAL SYS DUCTS PN 300-0674-1, 300-0675-1 & 300-0676-1 WITH SERVICEABLE UNITS. PN 300-0674-1 SHOWED EVIDENCE OF OVERHEATING. THE CABIN DUCT TEMP THERMISTOR PN 300-0751-1 & THE COCKPIT TEMP THERMISTOR PN 300-0565-2 WERE FOUND TO BE OUT OF RANGE, UNSERVICEABLE, & REPLACED WITH SERVICEABLE UNITS, THE TEMP CONTROLLER PN 300-0750-3 WAS REPLACED WITH A SERVICEABLE UNIT. ENVIRONMENTAL FUNCTION AND SYSTEM CHECKS WERE COMPLETED IAW CHAPTER 21 OF THE MM. SYS CHECKED SERVICEABLE & THE ACFT WAS RETURNED TO OPERATIONAL SERVICE.