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Test A: A/C Compressor Does Not Operate

WARNING: This page is about a different car, the 2002 Saturn LW300, 2002 Saturn LW200, 2002 Saturn L300, 2002 Saturn L200, and 2002 Saturn L100. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Ensure A/C system is properly charged. When checking A/C compressor operation or for battery voltage, ensure HVAC fan switch is not in OFF position. Ensure A/C switch is in ON (latched) position. Check for Powertrain Control Module (PCM) for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM.
NOTE: For circuit reference, see CONNECTOR IDENTIFICATION  and/or WIRING DIAGRAMS  .
  1. Turn ignition on. Verify operation of blower motor in all speeds. If blower motor operates correctly, go to next step. If blower motor does not operate correctly, diagnose by symptom. See SYMPTOM TEST DIRECTORY  table.
  2. With HVAC fan switch in ON position and A/C switch in ON (latched) position, does indicator lamp on A/C switch illuminate? If A/C switch indicator lamp does not illuminate, go to next step. If A/C switch indicator lamp illuminates, go to step  5 .
  3. With parking lights on, does HVAC control head backlighting operate? If backlighting does not operate, go to next step. If backlighting operates, replace HVAC control head. See HVAC CONTROL HEAD  under REMOVAL & INSTALLATION.
  4. Check continuity between HVAC control head terminal A3 and ground. If continuity does not exist, locate and repair open between HVAC control head connector and ground. If continuity exists, replace HVAC control head. See HVAC CONTROL HEAD  under REMOVAL & INSTALLATION.
  5. Check A/C fuse (10-amp) located in underhood fuse block. If fuse is blown, go to next step. If fuse is okay, go to step  7 .
  6. Check for the following:
    • A short to ground between underhood fuse blockconnector C1 terminal E4 and A/C compressor.
    • Remove A/C diode from underhood fuse block and ensure proper diode operation.
    • Ensure resistance of compressor clutch coil is 3-4 ohms while hot and cold.

    Repair or replace as necessary. After repairs are complete, check compressor operation.

  7. Turn ignition off. Replace A/C control relay in underhood fuse block with a known good relay (keep old relay). Start engine. Check A/C compressor operation. If A/C compressor does not operate, turn ignition off, reinstall original relay and go to next step. If A/C compressor operates, install a NEW A/C compressor relay. After repairs are complete, check compressor operation.
  8. Turn ignition on. Measure voltage between A/C compressor clutch connector terminal "B" and ground. If battery voltage is present, go to next step. If battery voltage is not present, go to step  10 .
  9. Turn ignition off. Check for and open circuit between A/C compressor clutch connector terminal "A" and ground. If circuit is open, repair wiring as necessary. If circuit is okay, replace A/C compressor clutch. See COMPRESSOR SERVICING article in GENERAL SERVICING. After repairs are complete, check compressor operation.
  10. Turn ignition off. Disconnect Body Control Module (BCM) 16-pin connector J1. Turn ignition on. Measure voltage between BCM connector J1, terminal B8 and ground. If battery voltage is not present, go to next step. If battery voltage is present, turn ignition off and go to step  12 .
  11. Turn ignition off. Check for an open circuit between BCM connector J1, terminal B8 and HVAC control head connector terminal B5. Repair circuit as necessary. If open is not detected, replace HVAC control head. See HVAC CONTROL HEAD  under REMOVAL & INSTALLATION. After repairs are complete, check compressor operation.
  12. Turn ignition off.
    • On 2.2L models, disconnect PCM connector J1 and connect a fused jumper between connector J1, terminal 47 and ground.
    • On 3.0L models, disconnect Engine Control Module (ECM) connector J2 and connect a fused jumper between connector J2, terminal 13 and ground.
    Turn ignition on. Check compressor clutch operation. If A/C compressor clutch does not operate, go to next step. If compressor clutch operates, replace PCM on 2.2L models or ECM on 3.0L models. See COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - SATURN "L" SERIES article in ENGINE PERFORMANCE. After repairs are complete, check compressor operation.
  13. Turn ignition on. Measure voltage between under hood fuse block connector C1, terminal C4 and ground. If battery voltage is present, go to next step. If battery voltage is not present, check A/C relay. If relay is faulty, install a NEW A/C relay. If A/C relay is okay, replace under hood fuse block. After repairs are complete, check compressor operation.
  14. Check for following:
    • On 2.2L models, check for an open circuit between under hood fuse block connector C1 terminal, C4 and PCM connector J1, terminal 47.
    • On 3.0L models, check for an open circuit between under hood fuse block connector C1 terminal, C4 and ECM connector J2, terminal 13.
    If open is not detected, go to next step. If an open is detected, locate and repair open as necessary. After repairs are complete, check compressor operation.
  15. Turn ignition on. Check for voltage between under hood fuse block connector C1 terminal, E4 and ground. If battery voltage is present, repair open in circuit between under hood fuse block connector C1 terminal, E4 and A/C compressor connector terminal "B". If battery voltage is not present, check A/C relay. If relay is faulty, install a NEW A/C relay. If A/C relay is okay, replace under hood fuse block. After repairs are complete, check compressor operation.
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