Mooney M20V - Page 157

MOONEY INTERNATIONAL CORPORATION
M20V SERVICE AND MAINTENANCE MANUAL
Page
Date
18
MAR 2017
Rev Date
21-57-00 - TROUBLESHOOTING R- 134a AIR CONDITIONING SYSTEM
There may be a time when the system does not operate and/or perform in accordance with information contained
herein.
Therefore, it is necessary for the service personnel to diagnose the discrepancy by troubleshooting the system and
its components. To assist in this diagnosis the following troubleshooting list is provided.
INDICATION PROBABLE CAUSE POSSIBLE SOLUTION
A. No system power 1. Ground power not connected 1. Plug in ground power cart
2. Aircraft power switch OFF 2. Energize power switch
B. Power ON but system will not op-
erate
1. Aircond. Control CB OFF 1. Energize air conditioning CB
2. Aircond. CB failed 2. Replace
3. Aircond. Mode SW failed 3. Replace
4. Relay(s) failed 4. Replace
5. Failed pressure switch 5. Replace
6. Failed power contactor 6. Replace
7. Failed motor drive 7. Replace
8. Vented system 8. Pressure check, evacuate &
charge
9. Low ambient temperature 9. Normal cutout function
10. Drive motor fuse blown 10. Replace
11. Drive motor temp. SW failed 11. Replace switch
12. Contactor control line fuse
blown
12. Replace fuse
C. System operates but does not
cool
1. Low refrigerant charge 1. Charge as necessary
2. Overcharged system cutout 2. Reclaim refrigerant as necessary
3. Failed compressor 3. Replace
4. Failed drive motor 4. Replace
5. Broken belt 5. Replace
6. Failed expansion valve(s) 6. Replace
7. Evap. Blower switch failed 7. Replace
8. Evap. Blower(s) motor failed 8. Replace
9. Evap. Blower(s) relay failed 9. Replace
10. Evap. Blower(s) C/B – OFF 10. Replace
11. Relay(s) failed 11. Replace
12. Evap. Module air inlet clogged 12. Remove debris
13. Exh. Valve inlet clogged 13. Remove debris
14. Excessive moisture in system 14. Replace rec- dryer assembly
15. Excessive oil in system 15. Drain excessive oil
21-57-00