How to Diagnose a Non-Functioning Radiator Fan in a Mercedes S430?
Diagnosing a Non-Functioning Radiator Fan in a Mercedes S430
If your Mercedes S430 radiator fan has stopped working even after replacing the fan motor and controller, there are several potential causes and steps you can take to diagnose and resolve the issue. Below is a comprehensive guide to help you troubleshoot this problem effectively.
Step 1: Verify Power Supply
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Check Voltage at the Connector:
- Ensure that there is a steady 12 volts at the fan connector.
- Confirm that the ground connection is secure.
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Inspect Wiring:
- Examine the wiring harness for any visible damage, corrosion, or loose connections.
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Test the Controller:
- If you have a multimeter, measure the voltage at the small wire leading to the controller. You mentioned that you get 12 volts here, which is good.
Step 2: Evaluate the Signal from the ECM
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Check ECM Output:
- You noted receiving a weak signal of 0.38 volts and 7 Hz from the ECM. This is concerning, as the signal should be stronger.
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