Problem:Compressor Clutch Inoperative - (Pages 16 - 23)626 Gasoline
Test Conditions: (1) Key at "ON" (Engine off)(2) Fan speed at "1"
Note: Air should flow from outlets. If no air flow, see Blower Motor Inoperative (626 FWD) in the 1983 Technical & Troubleshooting Manual before proceeding.
Note: The pressure setting of the low pressure switch prior to evaporator serial #G1-020642 (standard steering) G2-053312 (power steering) and H2-00135 (Puerto Rico) was 40 PSI when the ambient temperature is 50~F or higher.
MANIFOLD GAUGE:
Step 1. Connect a manifold gauge set to the service valves and observe the refrigerant pressure.
Note: The ambient temperature must be 32~F (0~C) or above.
CHECKING RESULTS
A. If the refrigerant pressure is below 30 +/- 3 PSI (2.11 kg/sq.cm) check the system for a refrigerant leak.
B. If the refrigerant pressure is above 30 +/- 3 PSI (2.11 kg/sq.cm) proceed to Step 2.
FUSE BLOCK:
Step 2. Check to make sure that the following (5) fuses are ok before proceeding to Step 3.
FUSE NAME AMP.
Engine 15
Cooling Fan 20
Air Cond. 15
Meter 10
Audio 15
Use the designated fuse if blown.
INDICATOR LIGHT:
Step 3. Turn on the A/C switch and observe the condition of the indicator light.
CHECKING RESULTS
A. If the indicator light comes on, proceed to Step 18.
B. If the indicator light stays off, proceed to Step 4.
C. If the indicator light starts flashing immediately proceed to Step 11.
D. If the initial complaint is that the A/C indicator light would start flashing at approximately 3 minutes after the A/C switch is turned on, while engine running, proceed to Step 14.
S.H.S. CONTROL BOX CHECK:
COLOR CODE CHANGE:
Step 4. Using a voltmeter, check the blue wire for power (approximately 12 volts) at the S.H.S. control box connector.
CHECKING RESULTS
A. If power exists, proceed to Step 5.
B. If no power exists, check the blue wire for a loss of continuity between the 15 AMP fuse marked "Audio" and the S.H.S. control box connector.
Note: Color Code Change
BLACK WIRE, GROUND AT S.H.S. CONTROL BOX:
Step 5. Ground the black wire at the S.H.S. control box connector.
CHECKING RESULTS
A. If the compressor clutch does not engage, proceed to Step 6.
B. If the compressor clutch engages, check the black wire for a loss of continuity between ground and the S.H.S. control box connector.
GREEN WIRE, GROUND AT S.H.S. CONTROL BOX:
Step 6. Ground the green wire at the S.H.S. control box connector.
CHECKING RESULTS
A. If the compressor clutch engages, proceed to Step 7.
B. If the compressor clutch does not engage proceed to Step 18.
A/C SWITCH CONNECTOR:
Step 7. Ground the blue-green wire at the A/C switch connector.
CHECKING RESULTS
A. If the compressor clutch engages proceed to Step 8.
B. If the compressor clutch does not engage, check the green wire for a loss of continuity between the S.H.S. control box to the A/C switch connector. If the green wire is ok, replace the A/C switch.
A/C RELAY #3 CONNECTOR, BLUE-GREEN WIRE CHECK:
Step 8. Ground the blue-green wire at the A/C relay #3 connector.
Note: You will notice (2) relays located next to each other, check wire color codes for positive identification.
CHECKING RESULTS
A. If the compressor clutch engages, proceed to Step 9.
B. If the compressor clutch does not engage, check the blue-green wire for a loss of continuity between the A/C switch connector and the A/C relay #3 connector.
A/C RELAY #3 CONNECTOR, YELLOW WIRE CHECK:
Step 9. Check the yellow wire for power at the A/C relay #3 connector.
CHECKING RESULTS
A. If no power exists in the yellow wire, check for a loss of continuity between the 20 AMP fuse marked "Cooling Fan" and the A/C relay #3.
APPLYING 12 VOLTS TO TERMINALS:
B. If power exists, follow the (3) steps below in order to troubleshoot the A/C relay #3.
(1) Remove A/C relay #3 from connector.
(2) Apply 12 volts to terminals 1 & 2 as shown.
(3) Using OHM meter, check for continuity between terminals 3 & 4 as shown.
^ If continuity exists, reconnect the A/C relay #3 and proceed to Step 10.
^ If no continuity exists, replace the relay.
BLUE-YELLOW AND BLACK, GROUNDTO A/C RELAY #3 CONNECTOR:
Step 10. Separately ground the blue-yellow and black wire at the A/C relay #3 connector.
CHECKING RESULTS
A. If the compressor clutch engages when grounding the blue-yellow wire, check it for a loss of continuity between the blower motor resistor and the A/C relay #3 connector.
B. If the compressor clutch engages when grounding the black wire, check for a loss of continuity between ground and the A/C relay #3 connector.
GREEN-WHITE WIRE CHECK:
Step 11. Using a voltmeter, check the green-white wire for power at the S.H.S. control box connector.
CHECKING RESULTS
A. If more than 1 volt exists, proceed to Step 12.
B. If 0-1 volts exist, turn the A/C switch off and then back on. If the indicator light continues to flash, replace the S.H.S. control box.
GREEN-WHITE WIRE CHECK AT LOW PRESSURE SWITCH:
Step 12. Remove the boot connector from the low pressure switch and check the green-white wire for power.
CHECKING RESULTS
A. If power exists, proceed to Step 13.
B. If no power exists in the green-white wire, check for a loss of continuity between the S.H.S. connector and the low pressure switch boot connector.
JUMPER WIRE LOCATION:
Step 13. Insert a jumper wire across both terminal ends of the low pressure switch boot connector.
Note: Before proceeding, turn the A/C switch off and then back on.
CHECKING RESULTS
A. If the indicator light continues to flash, check the black wire for a loss of continuity between ground and the low pressure switch boot connector.
B. If the indicator light stays on, discharge the refrigerant gas and change the low pressure switch.
YELLOW WIRE CHECK AT S.H.S. CONTROL BOX CONNECTOR:
Step 14. Using a voltmeter, check the yellow wire for power at the S.H.S. control box connector.
CHECKING RESULTS
A. If 0-1 volts exist, proceed to Step 15.
B. If over 1 volt exist, proceed to Step 16.
YELLOW WIRE AT THE SUPER HEAT SWITCH CONNECTOR:
Step 15. Disconnect the yellow wire at the super heat switch connector. Turn the A/C switch off and then back on.
CHECKING RESULTS
A. If the indicator light does not start to flash in approximately 3 minutes, discharge the refrigerant gas and replace the super heat switch.
B. If the indicator light starts flashing in approximately 3 minutes, check the yellow wire for a direct short to ground between the S.H.S. control box to super heat switch connector.
BLUE-BLACK WIRE CHECK:
Step 16. Using a voltmeter, check the blue-black wire for power at the S.H.S. control box connector.
CHECKING RESULTS
A. If over 5 volts exist, replace the S.H.S. control box.
B. If 0-5 volts exist, proceed to Step 17.
BLUE-WHITE WIRE CHECK:
Step 17. Using a voltmeter, check the blue-white wire for power at the S.H.S. control box.
CHECKING RESULTS
A. If over 5 volts exist, replace the S.H.S. control box.
B. If 0-5 volts exist proceed to Step 18.
BLUE A/C RELAY #2 CONNECTOR CHECK:
CONNECTOR TO A/C RELAY #2:
Step 18 Check the blue wire for power at the A/C relay #2 connector.
Note: You will notice (2) relays located next to each other, check wire color codes for positive identification.
CHECKING RESULTS
A. If no power exists in the blue wire, check for a loss of continuity between the A/C switch connector and A/C relay #2.
B. If power exists in the blue wire, follow the (3) steps below in order to troubleshoot the A/C relay #2.
(1) Remove A/C relay #2 from connector.
(2) Apply 12 volts to terminals 1 & 2 as shown.
(3) Using an OHM meter, check for continuity between terminals 3 & 4 as shown.
^ If continuity exists, reconnect the A/C relay #2 and proceed to step 19.
^ If no continuity exists, replace the relay.
BLUE-WHITE WIRE GROUND AT A/C RELAY #2 CONNECTOR:
Step 19. Ground the blue-white wire at the A/C relay #2 connector.
CHECKING RESULTS
A. If the compressor clutch engages, proceed to Step 20.
B. If the compressor clutch does not engage, proceed to Step 21.
JUMPER WIRE BLUE-WHITE WIRE TO S.H.S. CONNECTOR:
Step 20. Use a jumper wire between the blue-white wire of the A/C relay #2 connector and the blue-white wire of the S.H.S. control box connector.
CHECKING RESULTS
A. If the compressor clutch engages, check the blue-white wire for a loss of continuity between A/C relay #2 connector and S.H.S. control box connector.
B. If the compressor clutch does not engage, replace the S.H.S. control box.
BLUE-YELLOW WIRE CHECK:
COLOR CODE CHANGES:
Step 21. Check the blue-yellow wire for power at the A/C relay #2 connector.
CHECKING RESULTS
A. If power exists, proceed to Step 22.
B. If no power exists, check the blue-green wire for a loss of continuity between the 15 AMP fuse marked "Air Cond" and the A/C relay #2 connector.
Note: Color Code Changes
FROST SWITCH TEST:
Step 22. Check the blue-green and blue-yellow wire for power at the frost switch connector.
CHECKING RESULTS
A. If power exists in both wires, proceed to Step 23.
B. If no power exists in the blue-yellow wire, check for a loss of continuity between A/C relay #2 connector and frost switch connector.
C. If power exists in only the blue-yellow wire, follow the (4) steps below in order to troubleshoot the frost switch.
(1) Disconnect the wire connectors from the thermostat.
FROST SWITCH TEST:
(2) Using an ohmmeter, check for continuity between both terminals of the frost switch.
Note: The ambient temperature should be higher than 46~F (5~C).
^ If continuity exists, proceed to step 23.
^ If no continuity exists, proceed to step
(3) below.
(3) Place the capillary tube of the thermostat in a mixture of salt and ice water.
(4) Check the cut-in and cut-off temperature according to the following specification.
CUT-IN CUT-OFF
5 +/- 1~C (46 +/- 2.0~F) 1 +/- 1~C (34 +/- 2.0~F)
BLUE-GREEN WIRE CHECK AT COMPRESSOR CLUTCH CONNECTOR:
Step 23. Check the blue-green wire for power at the compressor clutch connector.
CHECKING RESULTS
A. If no power exists, check the blue-green wire for a loss of continuity between the frost switch connector and compressor clutch connector.
B. If power exists, repair or replace the magnetic clutch.