Testing a clockspring (also known as a spiral cable or coil spring) for continuity ensures that the electrical connections to steering wheel-mounted components (e.g., airbag, horn, or steering wheel controls) are intact. We have a video demonstrating how to test resistance. In the video, a belt is used for the demonstration, but the same testing method can be applied to seat belts, anchors, buckles, collapsible steering columns, roll-over bars, and positive battery terminals or cables. Please click here for the video.
Here's a step-by-step guide:
Safety Precautions
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Disconnect the Battery:
- Turn off the ignition and disconnect the negative battery cable.
- Wait at least 10–15 minutes to ensure the airbag system is de-energized.
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Remove the Airbag Module:
- Follow manufacturer-specific instructions to remove the airbag safely. This often involves unbolting or unclipping it from the steering wheel.
Tools Needed
- Multimeter (with continuity testing function)
- Basic hand tools (screwdrivers, etc.)
Steps to Test the Clockspring
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Access the Clockspring:
- Remove the steering wheel to access the clockspring. Be careful not to damage the steering column or connectors.
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Set Up the Multimeter:
- Turn the multimeter to the continuity (or ohms) setting.
- Test the multimeter by touching its probes together to confirm it emits a tone or displays near-zero resistance.
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Identify the Clockspring Pins:
- Locate the clockspring's electrical connector(s).
- Refer to the vehicle's service manual for the pinout diagram to identify the appropriate pins for the circuits you’re testing (e.g., airbag, horn, or control switches).
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Test Continuity for Each Circuit:
- Place one probe of the multimeter on a pin at the clockspring's connector.
- Place the other probe on the corresponding pin at the other side of the clockspring.
- Check for continuity:
- Good Clockspring: A tone from the multimeter (or near-zero resistance) indicates a continuous circuit.
- Faulty Clockspring: No tone (or infinite resistance) indicates an open circuit or broken wire.
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Test Through the Full Range of Motion:
- Slowly turn the clockspring to simulate steering wheel movement.
- Observe the multimeter reading for any interruption in continuity, which would indicate an internal fault.
Results Interpretation
- Normal: Continuous tone or stable resistance reading across all tested pins throughout the turning range.
- Faulty: Intermittent or no continuity in one or more circuits, even at a specific steering angle.
Additional Notes
- Reinstallation: If the clockspring is functional, ensure it is reinstalled in its centered position to avoid damage when the steering wheel is turned.
- Replacement: If a fault is found, the clockspring must be replaced. It cannot be repaired due to its delicate internal construction.
- Professional Calibration: Some vehicles require clockspring recalibration after replacement or removal.
Testing the clockspring for continuity ensures safety-critical systems, such as the airbag and horn, are functioning correctly. Always refer to the vehicle-specific service manual for detailed procedures and precautions.