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Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 358 (Electric Cooling Fan) >> System Tests >> Test B: Cooling Fan Inoperative

Test B: Cooling Fan Inoperative

WARNING: This page is about a different car, the 2002 Chevrolet Monte Carlo and 2002 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: This symptom occurs when one or both engine cooling fan motors do not operate properly in high or low speed modes.
NOTE: To identify system wiring schematics, see WIRING DIAGRAMS  .
NOTE: When checking or testing a connector end view, see CONNECTOR IDENTIFICATION  .
  1. Did you perform the DIAGNOSTIC SYSTEM CHECK (ENGINE COOLING)? If so, proceed to next step. If not, see DIAGNOSTIC SYSTEM CHECK (ENGINE COOLING)  under SELF-DIAGNOSTIC SYSTEM.
  2. Install a scan tool. Turn on ignition, with engine off. With a scan tool, command the low speed fan ON and OFF. Do the low speed engine cooling fans turn on and off with each command? If so, proceed to next step. If not, go to step  4 .
    3. NOTE: A 3-second delay occurs before the PCM changes the cooling fan speed.
  3. With a scan tool, command the fans high speed ON and OFF. Do the high speed engine cooling fans turn on and off with each command? If so, test for intermittent and poor connections. If not, go to step  12 .
    4. NOTE: Do not remove the 20-amp fused jumper wire connected during this step. Use a second 20-amp fused jumper wire while performing the following steps.
  4. Remove the cooling fan one relay. Connect a 20-amp fused jumper between the battery positive switch side voltage circuit and the cooling fan motor supply voltage circuit of the cooling fan one relay. Do both cooling fans operate in low speed? If so, go to step  22 . If not, proceed to next step.
  5. Disconnect the cooling fan 2 relay. Connect the second 20-amp fused jumper between the cooling fan low reference circuit and the cooling fan motor supply voltage circuit of the cooling fan 2 relay. Do both cooling fans operate in low speed? If so, go to step  23 . If not, proceed to next step.
  6. Connect the second 20-amp fused jumper between the battery positive voltage circuit and the cooling fan motor supply voltage circuit of the cooling fan 2 relay. Does the left cooling fan operate in high speed? If so, go to step  9 . If not, proceed to next step.
  7. Install the cooling fan 2 relay. Disconnect the left cooling fan electrical connector. Connect the second 20-amp fused jumper wire from the cooling fan motor supply voltage circuit to the ground circuit of the left cooling fan electrical connector. Does the right cooling fan operate in high speed? If so, go to step  25 . If not, proceed to next step.
  8. Connect the second 20-amp fused jumper wire from the cooling fan motor supply voltage circuit of the left cooling fan electrical connector to a good ground. Does the right cooling fan operate in high speed? If so, go to step  29 . If not, go to step  30 .
  9. Install the cooling fan 2 relay. Disconnect the right cooling fan electrical connector. Connect the second 20-amp fused jumper wire from the cooling fan motor supply voltage circuit to the cooling fan low reference circuit of the right cooling fan electrical connector. Does the left cooling fan operate in high speed? If so, go to step  26 . If not, proceed to next step.
  10. Connect the second 20-amp fused jumper wire from the coil side battery positive voltage circuit to the cooling fan low reference circuit of the of the right cooling fan electrical connector. Does the left cooling fan operate in high speed? If so, proceed to next step. If not, go to step  31 .
  11. Probe the battery positive voltage circuit on the switch side of the cooling fan one relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? If so, go to step  27 . If not, go to step  32 .
  12. Is the left cooling fan operating properly in high speed? If so, go to step  19 . If not, proceed to next step.
  13. Turn off the ignition. Disconnect the cooling fan 3 relay. Turn on the ignition, with the engine off. Connect a test lamp between the high speed cooling fan relay control circuit and the battery positive voltage circuit on the coil side of the cooling fan 3 relay. With a scan tool command the high speed fans ON and OFF. Does the test lamp turn on and off with each command? If so, go to step  15 . If not, proceed to next step.
  14. Probe the battery positive voltage circuit on the coil side of the cooling fan 3 relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? If so, go to step  34 . If not, go to step  33 .
  15. Install a 20-amp fused jumper between the battery positive voltage circuit on the switch side of the cooling fan 3 relay and the cooling fan motor supply voltage circuit. Does the left cooling fan operate in high speed? If so, go to step  24 . If not, proceed to next step.
  16. Probe the battery positive voltage circuit on the switch side of the cooling fan 3 relay with a test lamp connected to a good ground. Does the test lamp illuminate? If so, proceed to next step. If not, go to step  33 .
  17. With the 20-amp fused jumper still installed. Disconnect the left cooling fan electrical connector. Connect a test lamp from the cooling fan motor supply voltage circuit to the ground circuit of the left cooling fan electrical connector. Does the test lamp illuminate? If so, go to step  25 . If not, proceed to next step.
  18. Probe the cooling fan motor supply voltage circuit of the left cooling fan electrical connector with a test lamp that is connected to a good ground. Does the test lamp illuminate? If so, go to step  29 . If not, go to step  30 .
  19. Turn off the ignition. Disconnect the cooling fan 2 relay Turn on the ignition, with the engine off. Connect a 20-amp fused jumper between the cooling fan low reference circuit and the ground circuit of the cooling fan 2 relay. With a scan tool command the fans high speed ON and OFF. Does the right cooling fan operate in high speed? If so, proceed to next step. If not, go to step  28 .
  20. Connect a test lamp between the high speed cooling fan relay control circuit of the cooling fan 2 relay and the battery positive voltage circuit of the cooling fan 2 relay. With a scan tool command the fans high speed ON and OFF. Does the test lamp turn on and off with each command? If so, go to step  23 . If not, proceed to next step.
  21. Probe the battery positive voltage circuit of the cooling fan 2 relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? If so, go to step  34 . If not, go to step  33 .
  22. Inspect for poor connections at the cooling fan one relay. Did you find and correct the condition? If so, go to step  40 . If not, go to step  35 .
  23. Inspect for poor connections at the cooling fan 2 relay. Did you find and correct the condition? If so, go to step  40 . If not, go to step  36 .
  24. Inspect for poor connections at the cooling fan 3 relay. Did you find and correct the condition? If so, go to step  40 . If not, go to step  37 .
  25. Inspect for poor connections at the harness connector of the left cooling fan. Did you find and correct the condition? If so, go to step  40 . If not, go to step  38 .
  26. Inspect for poor connections at the harness connector of the right cooling fan. Did you find and correct the condition? If so, go to step  40 . If not, go to step  39 .
  27. Repair the right cooling fan motor supply voltage circuit for an open. When complete, go to step  40 .
  28. Repair the right cooling fan ground circuit for an open. When complete, go to step  40 .
  29. Repair the left cooling fan ground circuit for an open. When complete, go to step  40 .
  30. Repair the left cooling fan motor supply voltage circuit for an open. When complete, go to step  40 .
  31. Repair the right cooling fan low reference circuit for a short to ground or an open. When complete, go to step  40 .
  32. Repair the cooling fan one relay battery positive voltage circuit for an open. When complete, go to step  40 .
  33. Repair the battery positive voltage circuit for the cooling fan 2 and 3 relay for an open. When complete, go to step  40 .
  34. Repair the high speed cooling fan relay control circuit for an open. When complete, go to step  40 .
  35. Replace the cooling fan one relay. When complete, go to step  40 .
  36. Replace the cooling fan 2 relay. When complete, go to step  40 .
  37. Replace the cooling fan 3 relay. When complete, go to step  40 .
  38. Replace the left cooling fan. See FAN SHROUD  under REMOVAL & INSTALLATION. When complete, go to step  40 .
  39. Replace the right cooling fan. See FAN SHROUD  under REMOVAL & INSTALLATION. When complete, proceed to next step.
  40. Operate the system in order to verify the repair. Did you correct the condition? If so, system is okay. If not, go to step  3 .
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