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HOMESERVICE MANUALSDODGE AND RAM1999DAKOTA SLT, 2D PICKUP, 3.9 X, 4WD, STANDARDREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMENGINE CONTROLS - TESTS W/CODESSELF-DIAGNOSTIC TESTSNTC-20A: CHECKING A/C SYSTEM
1999 Dodge and Ram Dakota SLT, 2D Pickup, 3.9 X, 4WD, Standard

NTC-20A: Checking A/C System

1999 Dodge and Ram Dakota SLT, 2D Pickup, 3.9 X, 4WD, StandardSECTION NTC-20A: Checking A/C System
  1. If DTC P0645: A/C CLUTCH RELAY CIRCUIT is present, perform DTC P0645: A/C CLUTCH RELAY CIRCUIT  test. If DTC P0645 is not present, go to next step.
  2. Turn ignition on, with engine off. Using scan tool, monitor A/C REQUEST state. Turn A/C switch on and A/C fan on high. If A/C REQUEST state does not change, go to step 10). If A/C REQUEST state changes, go to next step.
  3. Ensure ignition is on, with engine off. Using scan tool, monitor A/C SELECT state. Turn A/C switch on and off several times. If A/C SELECT state does not change, repair open A/C select circuit. Perform TEST VER-2A. If A/C SELECT state changes, go to next step.
  4. Ensure ignition is on, with engine off. Using scan tool, actuate A/C clutch relay. If A/C clutch actuates, A/C clutch is operating properly at this time. Test is complete. If A/C clutch does not actuate, go to next step.
  5. Turn ignition off. Disconnect A/C clutch connector. Clean and/or repair connector as necessary. Turn ignition on, with engine off. Using scan tool, actuate A/C clutch relay. Connect a 12-volt test light across A/C clutch connector terminals. If test light blinks, replace A/C clutch coil. Perform TEST VER-2A. If test light does not blink, go to next step.
    NOTE: For circuit identification and wiring diagram, see appropriate wiring diagram in WIRING DIAGRAMS article.
  6. Turn ignition off. Remove A/C clutch relay. A/C clutch relay is located in Power Distribution Center (PDC). PDC is located next to battery. Refer to label under PDC cover for relay location. Disconnect A/C clutch connector. Clean and/or repair connectors as necessary. Using an ohmmeter, check resistance of A/C clutch relay output circuit from A/C clutch relay connector to A/C clutch coil. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open A/C clutch relay output circuit. Perform TEST VER-2A.
  7. Ensure ignition is off. Ensure A/C clutch relay is still removed. Reconnect A/C clutch connector. Using a 12-volt test light connected to ground, probe A/C clutch relay connector, fused B+ circuit. If test light does not illuminate brightly, repair open fused B+ circuit. Perform TEST VER-2A. If test light illuminates brightly, go to next step.
  8. Ensure ignition is off. Disconnect A/C clutch connector. Clean and/or repair connector as necessary. Using an ohmmeter, check resistance between ground and A/C clutch connector, ground circuit. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open ground circuit. Perform TEST VER-2A.
  9. At this time, A/C clutch relay is assumed to be defective. Replace A/C clutch relay. Perform TEST VER-2A.
  10. Turn ignition off. Ensure A/C system is properly charged. Recharge system as necessary. Perform TEST VER-2A. If A/C system is properly charged, go to next step
  11. Check clutch cycling high pressure cut-off switch. See CLUTCH CYCLING PRESSURE SWITCH in MANUAL A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. Replace high pressure cut-off switch as necessary Perform TEST VER-2A. If high pressure cutoff switch is okay, go to next step.
  12. Check clutch cycling low pressure cut-off switch. See CLUTCH CYCLING PRESSURE SWITCH in MANUAL A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. Replace low pressure cut-off switch as necessary. Perform TEST VER-2A. If low pressure cutoff switch is okay, go to next step.
  13. At this time, A/C clutch relay is assumed to be defective. Replace A/C clutch relay. Perform TEST VER-2A.
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