System Performance Test
No Cooling Or Insufficient Cooling1. Check A/C drive belt for proper tension. If A/C belt has proper tension, proceed to step 2. If not adjust as necessary.
2. Ensure A/C compressor rotates freely. If compressor rotates freely, proceed to step 3. If not, repair or replace as necessary.
3. With an A/C manifold set, check both high and low side pressures. If pressures are not correct, proceed to step 4. If both pressures are correct, proceed to step 5.
4. Check A/C system for leaks with a pump style halogen leak detector and repair or replace any leaking components. If no leaks are found, proceed to step 5.
5. Check for water in the system. If there is water, the receiver could be oversaturated causing an obstruction in refrigerant circulation. If water is found, replace receiver/drier and compressor, then recharge system. If no water is found, proceed to step 6.
6. If A/C manifold set reads 245kPa on low pressure side and 2257kPa on high pressure side and low pressure side piping is not cold when touched, air could be in the system. If air is found in the system, bleed down system and recharge. If no air is found in the system, proceed to step 7.
7. Using A/C manifold set check that refrigerant is circulating properly throughout the system. If refrigerant is not circulating properly, replace thermostatic expansion valve. If refrigerant is circulating properly, proceed to step 8.
8. Check for proper air distribution through evaporator and air ducts. If air is not circulating properly, repair as required. If air is circulating properly, proceed to step 9.
9. Inspect magnetic clutch, wiring fuses and circuit breaker for proper operation. Repair and replace as necessary. If no problems are found, proceed to step 10.
10. Jump battery voltage to magnetic clutch black/white terminal. If magnetic clutch fails to operate, replace clutch. If clutch operates, proceed to step 11.
11. With A/C and blower on, check if there is 12 volts at magnetic clutch black/white lead. If there is not 12 volts, check ground connection of magnetic clutch and repair as required. If there is 12 volts, proceed to step 12.
12. With A/C and blower on, check for 12 volts at A/C cut relay black/white terminal. If there is not 12 volts, locate and repair open circuit between A/C cut relay and magnetic clutch. If there is 12 volts, proceed to step 13.
13. With A/C off, check for continuity between A/C cut relay red/black and yellow/green terminals. If there is no continuity, replace A/C cut relay. If there is continuity, proceed to step 14.
14. With A/C and blower on, check for 12 volts at A/C cut relay yellow/green terminal. If there is not 12 volts, locate and repair open or short in wiring harness between A/C cut relay and main relay. If there is 12 volts, proceed to step 15.
15. With A/C off, check for continuity between A/C cut relay yellow/green terminal and ground. If there is no continuity, locate and repair open or short in wiring harness between A/C cut relay red/black terminal and ECA 1S terminal. If there is continuity, proceed to step 16.
16. With A/C and blower on, check for 12 volts at A/C cut relay black/green terminal. If there is not 12 volts, replace A/C cut relay. If there is 12 volts, proceed to step 17.
17. With A/C off, check for continuity between refrigerant pressure switch black/green terminals. If there is no continuity, replace refrigerant pressure switch. If there is continuity, proceed to step 18.
18. With A/C off, check for continuity green and black/green terminals on the thermostatic switch. If there is no continuity, replace thermostatic switch. If there is continuity, proceed to step 19.
19. With A/C and blower on, check for 12 volts [1][2]A/C relay No. 3 green terminal. If there are 12 volts, locate and repair open or short in wiring harness between A/C relay No. 3 and A/C cut relay. If there is not 12 volts, proceed to step 20.
20. With A/C and blower on, check for 12 volts at [1][2]A/C relay No. 3 blue/black terminal. If there is not 12 volts, locate and repair open or short in wiring harness between A/C relay No. 3 and battery. If there is 12 volts, proceed to step 21.
21. With A/C off, check for continuity between [1][2]A/C relay No. 3 yellow and blue terminals. If there is no continuity, replace A/C relay No. 3. If there is continuity, proceed to step 22.
22. With A/C and blower on, check for 12 volts at [1][2]A/C relay No. 3 yellow terminal. If there is not 12 volts, locate and repair open or short in wiring harness between A/C relay No. 3 and ignition switch. If there is 12 volts, proceed to step 23.
23. With A/C and blower on and ignition off, check for continuity between [1][2]A/C relay No. 3 blue terminal and ground. If there is continuity, replace A/C relay. If there is no continuity, proceed to step 24.
24. Check for continuity between [1][2]A/C relay No. 3 blue terminal and A/C switch blue terminal. If there is no continuity, locate and repair open in blue wire between A/C relay No. 3 and A/C switch. If there is continuity, proceed to step 25.
25. With A/C on and ignition off, check for continuity between A/C switch blue and yellow terminals. If there is no continuity, replace A/C switch. If there is continuity, proceed to step 26.
26. With A/C off, check for continuity between A/C switch blue/yellow terminal and blower control switch blue/yellow terminal. If there is no continuity, repair blue/yellow wire between A/C switch and blower control switch. If there is continuity refer to ``No Heater Blower Operation'' step 3.
No Engine Cooling Fan Operation
1. With A/C and blower on, check for 12 volts at [1][2]A/C relay No. 1 black/green wire. If there is not 12 volts, refer to ``No Cooling Or Insufficient Cooling'' step 18. If there is 12 volts, proceed to step 2.
2. With A/C off, check for continuity across [1][2]A/C relay No. 1 black/green wire to black wire. If there is no continuity, replace A/C relay No. 1. If there is continuity, proceed to step 3.
3. Check for continuity between [1][2]A/C relay No. 1 and both A/C relay black wires to ground. If there is no continuity, repair ground connections as required. If there is continuity, proceed to step 4.
4. With [1][2]A/C relay No. 1 connector disconnected, A/C and blower on and engine below 97°C, check for 12 volts at A/C relay yellow/green terminal. If there is not 12 volts, locate and repair open in yellow/green lead between A/C relay and cooling fan motor. If there is 12 volts, replace A/C relay No. 1.
No Condenser Fan Motor Operation
1. With A/C and blower on, check for 12 volts at [1][2]A/C relay No. 2 black/green wire. If there is not 12 volts, refer to ``No Cooling Or Insufficient Cooling'' step 18. If there is 12 volts, proceed to step 2.
2. With A/C off, check for continuity across [1][2]A/C relay No. 2 black/green wire, to black wire. If there is no continuity, replace A/C relay No. 2. If there is continuity, proceed to step 3.
3. Check for continuity at both [1][2]A/C relay No. 2 black wires to ground. If there is no continuity, repair grounds as required. If there is continuity, proceed to step 4.
4. With [1][2]A/C relay No. 2 green/red wire disconnected from relay, A/C and blower on, check for 12 volts at A/C relay green/red wire. If there is 12 volts, replace A/C No. 2 relay. If there is not 12 volts, proceed to step 5.
5. With A/C off, check for continuity from [1][2]A/C relay No. 2 green/red wire to condenser fan motor connector green/red wire. If there is no continuity, repair wire as required. If there is continuity, proceed to step 6.
6. With A/C on, check for 12 volts at condenser fan motor blue wire. If there is not 12 volts, check ignition switch circuit. If there is 12 volts, replace condenser fan motor.
Improper Cold Air Distribution
1. Set A/C for maximum cold position. Ensure mix door is in proper position. If air mix door is not in the proper position adjust cable as required. If door is in proper position, proceed to step 2.
2. With A/C set for maximum cold, check that fresh air door is in the proper position so as to allow only interior air to pass through or around the evaporator. If door is not in proper position, adjust cable as required. If door is in proper position, proceed to step 3.
3. With A/C set for maximum cold, check that function control door is in position so that air is distributed through center and side vents. If door is not in proper position, adjust cable as required. If door is in proper position, check for blockage in ducts and repair as required.