AirComm Corporation Bell 412 Air Conditioner Instructions for Continued Airworthiness with Ground Cooling User Manual

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 41 
CHAPTER 8 
TROUBLESHOOTING 
 
1. SYSTEM TROUBLESHOOTING 
 
Prior to troubleshooting a defective system, it is advisable to conduct a visual inspection for 
general condition, and obvious signs of damage or failure.  
 
The following matrix lists the easiest checks, and the most likely problems. 
 
Problem Probable Cause Solution 
System not Cooling 
(Evaporator blowers...

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 42 
 
(System troubleshooting continued) 
 
Problem Probable Cause Solution 
System not cooling 
(Evaporator blowers not 
operating) 
i. Forward and aft evaporator 
blower motor(s)   
 
     
i. Check for power to the 
motor(s), and for the free 
movement of the blower 
wheel. If the motor shaft 
does not turn smoothly the 
motor must be replaced. ¹ 
Loss of cooling limited to...

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 43 
412AC-810 ELECTRICAL SCHEMATIC 
  

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 44 
(412AC-810 ELECTRICAL SCHEMATIC CONTINUED) 
 
  

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 45 
(412AC-810 ELECTRICAL SCHEMATIC CONTINUED) 
 
(412AC-810 ELECTRICAL SCHEMATIC CONTINUED)  

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 46 
  

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 47 
 
Figure 13:  REFRIGERANT PLUMBING SCHEMATIC   

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 48 
(Refrigerant plumbing schematic continued) 
 
 
Figure 14:  Refrigerant plumbing schematic (continued) 
(REFRIGERANT PLUMBING SCHEMATIC CONTINUED)  

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 49 
  

                                                                      AIR CONDITIONER SERVICE MANUAL 412AC-210M 
Revision 7 Page 50 
412AC-820 ELECTRICAL SCHEMATIC