Upgrade Unleashed: How to Hook Up an RCA Adapter to Your Stock Radio and Supercharge Your Sound System

If you’re looking to enhance your car audio system without replacing your stock radio, connecting an RCA adapter is a smart and cost-effective solution. Stock radios often lack the features and audio quality of aftermarket units, but with an RCA adapter, you can easily integrate additional components like amplifiers, subwoofers, or other audio equipment to elevate your in-car audio experience. 

This simple yet effective process allows you to tap into your stock radio’s audio output and channel it through external devices, providing clearer sound, better bass response, and overall improved sound quality. In this guide, we’ll walk you through the step-by-step process of hooking up an RCA adapter to your stock radio, ensuring that you can enjoy enhanced audio performance while keeping your factory radio intact. 

What is an RCA Adaptor?

Before we dive into the steps of connecting an RCA adapter, it’s important to understand what it is and how it works. An RCA adapter, also known as a line output converter (LOC), is a device that converts high-level audio signals from your stock radio into low-level signals that can be used by external audio equipment such as amplifiers or subwoofers.

Factory head units rarely have RCA or “Low line” outputs which your amplifier will need for its input signal. This conversion process is necessary because most stock radios do not have RCA outputs, hence the need for an adapter to bridge the gap between the radio and additional audio components. 

RCA cables are typically used to transmit audio signals with left and right channels, making them an ideal choice for connecting to external devices. Head unit manufacturers use different types of high-level audio signals, so it’s essential to choose the right RCA adapter for your specific car model and radio brand. RCA adapter converter box/amp line output converters are available in various sizes, shapes, and configurations to accommodate different audio setups. 

Guide To Do, How To Hook Up RCA Adapter To Stock Radio

Now that you understand the basics of what an RCA adapter is, let’s get into the process of connecting it to your stock radio. The steps may vary slightly depending on your particular car model and radio brand, but the general process remains the same. 

Gather Your Materials 

First and foremost, you’ll need to have all the necessary materials for this project. These include: 

  • RCA adapter 
  • Wire strippers 
  • Electrical tape or heat shrink tubing
  • Screwdriver or drill (if mounting the adapter) 

Identify Your Radio’s Wires

The first step in connecting an RCA adapter is to locate the stock radio’s speaker wires. You can typically find these at the back of the stock head unit or behind the factory radio. Factory wiring diagrams can also help identify these wires if they are not easily accessible.

If you need help determining which wires are for your speakers, consult your car’s manual or use a multimeter to test for continuity. Once you’ve identified the speaker wires, it’s time to move on to the next step. The wires of the factory stereo system will be different colors, so be sure to follow the color codes provided by your adapter’s manual or instructions.  

Strip and Connect Wires

Using your wire strippers, strip a small section of insulation from each speaker wire that you will be connecting to the RCA adapter. Next, twist together the ends of each stripped wire with its corresponding input on the RCA adapter, making sure to match the left and right channels correctly. Once connected, secure each wire with electrical tape or heat shrink tubing.

Aftermarket external car amplifier RCA jacks usually come with inputs labeled “L+” and “R+,” denoting positive connections. In contrast, the “L-” and “R-” inputs are for negative connections. Make sure the car battery negative cable is disconnected for safety during installation. RCA output converter boxes will typically have an output labeled “Amp” or “Amplifier”, which is where you’ll connect your RCA cables to your amplifier’s input.

Connect RCA Cables

With the speaker wires connected to the RCA adapter, it’s time to plug in your RCA cables. If you’re using a standard pair of RCA cables, connect one end to the output on the adapter and the other end to your desired audio equipment input. Some adapters may come with additional outputs for multiple devices, so be sure to connect all necessary cables. RCA plugs are color-coded, making it easy to match the left and right channels. Speaker wires are also typically color-coded, so follow the same color scheme to ensure correct connections.  

 Test and Adjust Settings

Before mounting the RCA adapter or reassembling your car’s interior, it’s essential to test the connections and adjust any settings as needed. Turn on your radio and connected audio equipment to see if you’re getting sound output. If not, check all connections and make sure they are secure. 

Additionally, some head units may require adjustments in the settings to enable RCA outputs or adjust the signal level. Refer to your radio’s manual for specific instructions on how to do this.  

Mount the RCA Adapter (if necessary)

If your RCA adapter comes with a mounting bracket, you may choose to secure it in place using screws or adhesive. Be sure to choose a location that is easily accessible for future adjustments and won’t interfere with other components.

These are steps for a basic RCA adapter installation. However, if you’re not comfortable with DIY projects or have a more complex audio setup, it’s always best to consult a professional car audio installer for assistance. 

Use of RCA Adaptor To Stock Radio Elevates Music Experience

By now, you should have successfully connected an RCA adapter to your stock radio. This simple and affordable upgrade can significantly improve your in-car audio experience by giving you the ability to integrate external audio components like amplifiers and subwoofers.

With clearer sound, better bass response, and overall improved audio quality, listening to music on long drives or daily commutes will be a more enjoyable experience. So, next time you’re looking to upgrade your car’s audio system, remember the power of an RCA adapter and give it a try for yourself. 


Do stock radios have RCA jacks? 

No, most stock radios do not have RCA jacks for connecting external audio components. Hence the need for an RCA adapter to convert high-level signals into low-level ones. 

How do you wire an aftermarket amp to a factory radio? 

The process of wiring an aftermarket amp to a factory radio is similar to that of connecting an RCA adapter. However, in this case, you would connect the speaker wires directly to the amplifier’s inputs instead of using an adapter. 

Can you hook subs up to a stock radio? 

Yes, you can hook up subs to a stock radio by using an RCA adapter or wiring the speaker wires directly to the amplifier’s inputs. However, it’s essential to make sure your stock radio has enough power and capabilities to handle the additional load from subwoofers. So, be sure to check your car manual for specific information on your stock radio’s capacities and limitations.

Can I plug the jack into RCA?

No, you cannot plug a jack directly into an RCA adapter. Jacks and RCA cable has different connections, so it’s essential to use the appropriate cable for your setup. If your equipment has a jack output, you will need to use an adapter or converter to connect it to the RCA inputs on your adapter. Do not force a jack into an RCA input, as this can cause damage. 


In conclusion, connecting an RCA adapter to a stock radio is a relatively simple process that can greatly enhance your audio experience. By following the steps outlined earlier, you can successfully bridge the gap between your factory head unit and external audio components, such as amplifiers or subwoofers, without sacrificing audio quality. It’s essential to first identify the type of RCA adapter that suits your needs and ensure compatibility with your stock radio. 

Once you’ve gathered the necessary equipment and prepared your workspace, the installation process involves locating the appropriate connectors on your radio, plugging in the RCA adapter, and securing the connections to prevent interference or loss of signal quality. Always exercise caution during the process, taking care not to damage any existing components.

Ultimately, this upgrade empowers you to customize your car audio system, achieve better sound quality, and enjoy a more immersive and personalized in-car entertainment experience. So, don’t hesitate to give it a try and elevate your music experience on the road. That concludes our guide to installing an RCA adapter to a stock radio. Happy listening!