Bmw E90 Cigarette Lighter Fuse

The cigarette lighter, also known as the auxiliary power outlet, in a BMW E90 is a frequently used feature. From charging mobile phones to powering GPS devices, its functionality is crucial for many drivers. When this outlet stops working, a blown fuse is often the culprit. This article provides a comprehensive guide to identifying, replacing, and troubleshooting the BMW E90 cigarette lighter fuse.

Benefits of Understanding the Cigarette Lighter Fuse

Knowing the location and function of the cigarette lighter fuse in your BMW E90 offers several benefits:

• Convenience: Quickly restore power to essential devices while on the road.
• Cost Savings: Avoid expensive trips to the mechanic for a simple fuse replacement.
• Troubleshooting: Easily diagnose a non-functional cigarette lighter socket.
• Preventive Maintenance: Understanding the electrical system contributes to overall vehicle health.

Understanding the BMW E90 Cigarette Lighter Wiring Diagram

Before diving into fuse replacement, familiarity with the electrical system is essential. The BMW E90 cigarette lighter fuse is part of a larger circuit that protects other components. Consulting your vehicle’s wiring diagram can provide valuable insights:

• Fuse Location: The wiring diagram will pinpoint the exact location of the relevant fuse within the fuse box.
• Circuit Overview: Gain a better understanding of which other components share the same circuit.
• Voltage and Amperage: Identify the correct fuse amperage rating for replacement.

Typically, you can find a simplified diagram in your owner’s manual or a more detailed version in a repair manual specific to the BMW E90.

Practical Application

The following steps outline the process of replacing the BMW E90 cigarette lighter fuse:

1. Locate the Fuse Box: The fuse box is typically located in the glove compartment or behind a panel in the trunk. Refer to your owner’s manual for the precise location.
2. Identify the Correct Fuse: Use the fuse diagram (usually located on the inside of the fuse box cover) to identify the fuse associated with the cigarette lighter/auxiliary power outlet. Note the amperage rating.
3. Remove the Blown Fuse: Use a fuse puller (often found in the fuse box) to carefully remove the blown fuse.
4. Inspect the Fuse: Visually inspect the fuse. A blown fuse will have a broken filament.
5. Install a New Fuse: Replace the blown fuse with a new fuse of the exact same amperage rating. Using a fuse with a higher amperage rating can damage the electrical system and potentially cause a fire.
6. Test the Cigarette Lighter: Turn the ignition to the “on” position and test the cigarette lighter with a compatible device.

1. Troubleshooting Common Issues

Even after replacing the fuse, the cigarette lighter may not function correctly. Consider these troubleshooting steps:

• Check the Replacement Fuse: Ensure the new fuse is the correct amperage rating and is not blown.
• Inspect the Socket: Check the cigarette lighter socket for any debris or foreign objects that might be preventing proper contact.
• Wiring Problems: If the fuse continues to blow, there may be a short circuit in the wiring. This requires professional diagnosis.
• Device Compatibility: Verify the device you’re trying to power is compatible with the E90’s power outlet.

2. Tips for Best Practice

• Always use the correct fuse amperage rating.
• Keep spare fuses in your vehicle.
• Consult a qualified mechanic if you are unsure about any part of the process.
• Avoid overloading the cigarette lighter socket with multiple devices.

FAQs

Q: Where is the fuse box located in my BMW E90?
A: Typically in the glove compartment or behind a panel in the trunk. Refer to your owner’s manual for the exact location.

Q: What amperage fuse does the cigarette lighter use in a BMW E90?
A: The amperage can vary, but it’s usually between 15A and 20A. Check your owner’s manual or the fuse box diagram for the correct rating.

Q: What happens if I use a fuse with a higher amperage rating?
A: Using a higher amperage fuse can damage the electrical system and potentially cause a fire.

Q: Why does my cigarette lighter fuse keep blowing?
A: This could indicate a short circuit in the wiring or an overloaded circuit. Seek professional diagnosis.

Q: Can I use a USB adapter in the cigarette lighter socket?
A: Yes, USB adapters are commonly used to charge devices via the cigarette lighter socket.

Conclusion

Understanding and maintaining the BMW E90 cigarette lighter fuse is essential for ensuring the functionality of your vehicle’s auxiliary power outlet. By following the steps outlined in this guide, you can quickly diagnose and resolve common issues, saving time and money. However, always prioritize safety and consult a qualified mechanic when dealing with electrical issues beyond your comfort level.