How to Use a Fuse Tap for AutoJeweler LED Emblems & AccessoriesUpdated a day ago

A fuse tap (also called an add-a-fuse) lets you add a protected 12V accessory connection at the vehicle fuse box without cutting into a factory wire. AutoJeweler uses fuse-tap wiring on select LED emblem and accessory installations when a switched 12V source is needed.

What You Need

• A fuse tap that matches your vehicle's fuse type
• The original vehicle fuse from the circuit you are tapping
• The correct fuse for the added AutoJeweler accessory circuit, as specified for your kit
• A multimeter, test light, or power probe
• Wire crimpers if your fuse tap uses a crimp connection

Common automotive fuse styles include Micro2, Micro3, mini, low-profile mini, and standard blade. If your AutoJeweler harness includes multiple fuse-tap adapters, use the adapter that matches the fuse already installed in the vehicle. Never force the wrong fuse-tap size into the fuse box.

1. Decide Whether You Need Switched or Constant Power

For most AutoJeweler LED emblem installations, a switched 12V accessory source is preferred when you want the lighting system to power on with the vehicle and shut off when the vehicle is turned off.

• Switched power: 12V with the ignition/accessory circuit on, no power with the vehicle off.
• Constant power: 12V even when the vehicle is off.

Using constant power when the installation is intended for switched power can allow the controller or lighting product to remain powered after the vehicle is shut down.

2. Test the Fuse Slot Before Installing the Tap

Do not choose a fuse location based only on the label in the fuse-box diagram. Test it.

1. Turn the vehicle completely off.
2. Check the fuse with a multimeter, test light, or power probe.
3. Turn the ignition/accessory circuit on and test again.
4. Turn the vehicle off and confirm the power disappears again.

For a switched installation, the correct fuse location should have no power with the vehicle off, show approximately 12V when the ignition/accessory circuit is on, and lose power again when the vehicle is turned off.

3. Choose a Non-Critical Circuit

Avoid tapping into fuses that serve critical vehicle systems.

Do not use circuits for:

• Airbags / SRS
• ABS or stability-control systems
• ECU / PCM / engine management
• Fuel pump
• Transmission control
• Other critical safety or drivetrain systems

Accessory-style circuits such as a power outlet, radio/accessory circuit, heated seat, or other non-critical switched circuit may be better candidates, but fuse assignments vary by vehicle. Always verify the circuit with a meter before connecting.

4. Install the Original Fuse and Accessory Fuse

Remove the original fuse from the fuse slot you tested. Install that original fuse into the fuse tap so the factory circuit keeps its original protection. Install the appropriate fuse for the added AutoJeweler accessory circuit in the second fuse position.

5. Fuse-Tap Orientation Matters

An add-a-fuse can physically fit into many fuse slots in either direction, but the electrical orientation matters. The added accessory circuit should receive power through its fuse, not bypass it.

1. With the original fuse removed, identify which terminal of the fuse slot is the powered/hot side.
2. Position the fuse tap so incoming power enters the fuse tap on its supply side and passes through the accessory fuse before reaching the added wire.
3. Confirm the accessory lead is protected by the added fuse.

If you are not comfortable identifying the powered side of a fuse slot, have the fuse tap installed by a qualified automotive installer or electrician.

6. Connect the AutoJeweler Power Lead

For a typical two-wire AutoJeweler LED accessory:

• Red: positive 12V power
• Black: ground

Connect the positive lead to the fuse tap using the supplied connector or a properly crimped connection. Connect the ground wire to a clean factory ground point, clean unpainted chassis metal, or another approved ground location.

Do not assume wire colors or wiring are identical across every AutoJeweler product. Product-specific instructions take priority.

7. Test the System Before Final Assembly

1. Make sure the fuse tap is fully seated.
2. Turn the vehicle on.
3. Confirm the emblem, controller, or accessory powers up normally.
4. Turn the vehicle off.
5. Confirm the system shuts down if it is intended to use switched power.

If the lights stay on after the vehicle is off, the fuse location may have constant power or delayed accessory power. Test a different appropriate switched circuit if required.

8. Secure and Protect the Wiring

• Keep wiring away from exhaust components, engine heat, belts, fans, and other moving parts.
• Protect wires from sharp metal edges.
• Secure loose wiring with zip ties.
• Do not pinch the fuse-tap lead under the fuse-box cover.
• Make sure the fuse-box cover can close normally whenever possible.
• Keep non-waterproof controllers and connectors in a dry, protected location.

Troubleshooting

The lights do not turn on

• Confirm the selected fuse slot actually has power with the ignition/accessory circuit on.
• Make sure both fuses are installed correctly.
• Confirm the fuse tap is fully seated.
• Check the crimp or connector on the accessory wire.
• Check the ground connection.
• Verify the controller and all plugs are fully connected.

The lights stay on after the vehicle is off

The fuse location may have constant power or retained accessory power. Test the circuit after the vehicle has fully shut down and choose an appropriate switched circuit if your installation requires automatic on/off operation.

The accessory fuse keeps blowing

Stop testing. A repeated blown fuse can indicate a short circuit, damaged wiring, incorrect connection, overloaded circuit, or incorrect fuse rating. Inspect the wiring before replacing the fuse again.

The fuse-box cover will not close

Some fuse taps sit higher than the original fuse. Do not force the cover closed if it pinches the wire. Safely reroute the lead or choose another suitable fuse location.

Need Help?

If you are unsure which fuse location or fuse-tap adapter is correct for your vehicle, contact AutoJeweler Support with your vehicle year, make, model, product name, and clear photos of the fuse box and fuse type.

Professional installation is recommended if you are not comfortable testing automotive electrical circuits. AutoJeweler is not responsible for damage caused by improper wiring, incorrect fuse selection, short circuits, or installation into critical vehicle systems.

© AutoJeweler. All rights reserved.