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Checking Radiator Fan Performance With No DTCS

NOTE: For connector identification, see CONNECTOR IDENTIFICATION . For component location, see COMPONENT LOCATIONS . For circuit identification and wiring diagram, see WIRING DIAGRAMS . After each repair procedure has been completed, reconnect all components.
  1. Turn ignition on (engine not running). With the DRBIII®, actuate the Radiator Fan Relay. Does the Radiator Fan Motor cycle on and off? If yes, test is complete. If no, go to next step.
  2. Turn the ignition off. Remove the Radiator Fan Relay. Using a 12-volt test light connected to ground, probe the (C24) Fused B+ circuit in the Radiator Fan Relay connector. Did the light illuminate brightly? If yes, go to next step. If no, repair the open or short to ground in the (C24) Fused B+ circuit. Inspect the related fuse and repair as necessary. Perform POWERTRAIN VERIFICATION TEST VER-2 under VERIFICATION TESTS in SELF-DIAGNOSTICS - WRANGLER article.
  3. Turn ignition off. Disconnect the Radiator Fan Motor harness connector. Measure the resistance of the (K173) Radiator Fan Relay Control circuit from the PDC to the PCM harness connector. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the (K173) Radiator Fan Relay Control circuit. Perform POWERTRAIN VERIFICATION TEST VER-2 under VERIFICATION TESTS in SELF DIAGNOSTICS - WRANGLER article.
  4. Connect the PCM harness connectors. Install the Radiator Fan Relay. Ignition on, engine not running. With the DRBIII®, actuate the Radiator Fan Relay. Using a 12-volt test light connected to ground, backprobe the (C25) Radiator Fan Relay Output circuit in the Radiator Fan Motor harness connector. Does the test light cycle on and off? If yes, go to next step. If no, go to step  7.
  5. Turn the ignition off. Disconnect the Radiator Fan Motor harness connector. Measure the resistance between ground and the (Z212) Radiator Fan Motor ground circuit. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the (Z212) Radiator Fan ground circuit. Perform POWERTRAIN VERIFICATION TEST VER-2 under VERIFICATION TESTS in SELF-DIAGNOSTICS - WRANGLER article.
  6. If there are no possible causes remaining, replace the Radiator Fan Motor. Perform POWERTRAIN VERIFICATION TEST VER-2 under VERIFICATION TESTS in SELF-DIAGNOSTICS - WRANGLER article.
  7. Turn the ignition off. Disconnect the Radiator Fan Motor harness connector. Remove Radiator Fan Relay. Measure the resistance of the (C25) Radiator Fan Relay Output circuit between the Radiator Fan Motor harness connector and the Radiator Fan Relay connector. Is the resistance below 5.0 ohms? If yes, go to the next step. If no, repair the open in the (C25) Radiator Fan Relay Output circuit. Perform POWERTRAIN VERIFICATION TEST VER-2 under VERIFICATION TESTS in SELF-DIAGNOSTICS - WRANGLER article.
  8. Measure the resistance between ground and the (C25) Radiator Fan Relay Output circuit. Is the resistance below 100 ohms? If yes, repair the short to ground in the (C25) Radiator Fan Relay Output circuit. Perform POWERTRAIN VERIFICATION TEST VER-2 under VERIFICATION TESTS in SELF-DIAGNOSTICS - WRANGLER article. If no, go to next step.
  9. If there are no possible causes remaining, replace the Radiator Fan Relay. Perform POWERTRAIN VERIFICATION TEST VER-2 under VERIFICATION TESTS in SELF-DIAGNOSTICS - WRANGLER article.
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