For many of us, keeping our factory stereo in place is preferred. The clean look of a factory stereo, GPS features, and the cost of a new unit are a few reasons they are not replaced. However, many want to upgrade their sound system with an amplifier to provide more power to some aftermarket speakers. Unfortunately, factory stereos do not have the necessary preamp outputs needed that would allow you to easily connect an amplifier to it. The good news is that a LOC, or line output converter, is made for these situations and is an affordable option. These will convert the speaker-level output into an RCA signal, which will allow the connection to an amplifier. 

If you are looking to install a line output converter to deal with this situation, here are the steps and tips to get the job done!

Required Tools (may vary depending on the vehicle or installation needs):

  • Electrical Butt Connectors 
  • Wire Stripper
  • Electrical Tape
  • Voltmeter
  • Additional Wire (may be needed)
  • Screwdrivers
  • Panel removal tools
Belva BKIT150 Wire Terminal Kit with Wire Crimper/Stripper

Let’s take a look at the step-by-step instructions so you can get your install started. Keep in mind there are many variables with vehicles and equipment that may alter these steps.

1. Disconnect the negative battery terminal

Once you are ready to go, start by disconnecting the negative battery terminal. This step will help keep you and your equipment safe by preventing shorts,  blown fuses, and other electrical problems. 

2. Remove your factory head unit

Next, you will need to remove the head unit so you can locate the wiring that will connect to the line output converter. Refer to your vehicle’s instructions (online or in the manual) for carefully removing the necessary panels and bolts/screws to pry it loose.

3. Review your wiring diagrams

In order to understand where to connect your wires, you will need to ensure you understand your stereo output wiring. Refer to the wiring diagram for your stereo before proceeding to the next step. You will also want to familiarize yourself with the wiring or connection diagram and instructions of your select line output converter. This diagram will help you understand what each wire or connector terminal corresponds to so you know where to connect them. 

4. Strip Wires and Make the Proper Connections


Line output converters with wired connections

If you are using a LOC with wired connections like the NVX XFLOC4, you will want to follow these steps: Strip each of the wires (remove about 1 inch from each) on both the line output converter and the stereo wiring that will be connected. Next, make the proper connections, such as the front left to the front left, front right to the front right, etc. Use butt connectors (some prefer to solder) and wire crimpers to finalize. Add electrical tape around the connection and proceed until all wires are correctly connected together. Lastly, you will plug in the RCA cables to the line output converter and run and connect the RCA cables to the amplifier. If using the remote wiring you will also need to run that to the amplifier at this time.

Scosche SLC-4

Line output converters with speaker connector terminals

On a LOC that uses speaker connector terminals like the Scosche SLC-4, the process will be similar, but with just fewer steps. First, strip the wires from the stereo wiring and then make the proper connections with the corresponding speaker connector terminal. Make sure each wire is secure and the wire is not loose, but do not overtighten it. Then connect your RCA cables to the corresponding places on both your LOC and your amplifier.

5. Test your System and Tidy Up the Install

Now that all the wiring is completed, you will want to test your new amplifier. Connect your battery and turn on the stereo to ensure the amplifier, stereo, and speakers are working as expected. Make any necessary adjustments, if needed, and proceed to finalize your install. Clean up all wiring, secure the line output converter, and reinstall the stereo.

Installing a line output converter in your vehicle is relatively easy for those that are comfortable with the above steps. You can also check out the video above for a step by step walkthrough from one of our professional installers.


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