Stereo Wire Harness: An Ultimate Guide on Simplifying the Aftermarket Radio Installation in your Car

Installing aftermarket car stereos may seem daunting, but owning the stereo wire harness becomes easier.

Also, successful car stereo installation requires you to know the wire colors and the car’s stereo wiring diagram.

In this guide, you will get details related to the wire colors, installation procedures, harnesses, and others so you can do your job without errors.

So, let’s get started.

Aftermarket stereo harness

Aftermarket stereo harness

What do you mean by stereo harness?

Think of a harness as an adapter.

As you need an adaptor for the proper functioning of the devices, a harness also allows you to install the aftermarket car stereo effortlessly.

You can also use special harnesses that bypass built-in amplifiers, extend the wire length, and many other purposes.

Any stereo harness will work if compatible with the car and the aftermarket stereo.

You can find stereo harnesses at online and offline stores, but the main problem is finding the correct harness that suits both your car and the stereo.

Cloom can help you get a suitable harness for your car by customizing one according to your need.

Wiring harness

Wiring harness

Specialized harnesses for stereo:

The wiring system is diverse; thus, you can find various specialized stereo harnesses in the market.

Here are some types of special stereo harnesses. Find out whether they are of any use to you or not.

Extension harnesses:

Sometimes, cars have stereo connectors located at a distance from the stereo.

Some cars have stereo connectors in the trunk also. In all such cases, you may need extension harnesses to connect the connectors to the stereo.

As the name clears, these harnesses have long cables reaching any corner of your car.

Additionally, some advanced harnesses allow you to customize the cable lengths per the requirements.

Amplifier bypassing harnesses:

In some vehicles, the built-in amplifiers in the car are separate from the stock stereo system.

You can use the car amplifier with your aftermarket stereo system in this situation.

However, sometimes, there is a better amplifier in the aftermarket stereo system.

So, in that case, there is no need to use the stock amplifier, and you can bypass that stock amplifier with the help of specialized harnesses.

Safety alarm retainer:

Almost all modern cars come with safety alarm systems, and this safety system and the stock stereo system are installed in a few cars.

If you want to replace the stock stereo system with the aftermarket one, you may eliminate the alarm system.

However, with some specialized harnesses, you can retain the functioning of the safety alarm systems even after removing the stock stereo.

Programmable harness:

In some modern cars, such as Chrysler Uconnect, Ford Sync, and more, a few unique features come with the stock radio system, and replacing the stock system eliminates your access to all these systems.

Several programmable harnesses are pretty advanced and help you retain all the exquisite features even after you remove the stock radio.

Though these harnesses come at a hefty price, they are worth their price.

Auto wiring harness

How do I find a suitable wiring harness?

Selecting a suitable wiring harness requires some specific information, including general information about your car and the availability of certain features.

Some of the information that you must have includes:

  1. Year of the vehicle
  2. Make of the vehicle
  3. Model of the vehicle
  4. Does the vehicle have a factory amplified system?
  5. Does the owner have an aftermarket stereo system?

If the answer to question 5 is yes, you may not need a stereo harness, as shops installing the stereo use the wiring harness from the market.

If you have a factory-amplified system, you will need a specialized stereo harness to provide a low-level signal to the amplifier.

Car Stereo

Car Stereo

How can you install an aftermarket stereo using a harness?

If you use an aftermarket stereo harness for installing a new radio system to your car, it is easier than without one.

You need to match the car’s stereo wire colors with the colored slots of the stereo harness.

Once you match the colors, plug the harness’s other end into the car’s head unit.

In earlier times, color codes on the wires used to vary from brand to brand and even from model to model in some cases.

However, nowadays, car manufacturers follow a standard radio wire color system.

Mostly, your car and the aftermarket stereo have a diagram that makes it easy to connect the stereo with the harnesses.

However, if you do not find any such diagram, follow the standardized color codes of the stereo wires mentioned below. 

You can divide these wires into four main types. Here are the types with their color codes:

  • Ground wire: A single black wire among many stereo wires is the ground wire.
  • Power wires: There are three in number; yellow for a constant power supply of 12 V, red for accessories, and orange with white stripes for dimmer and illumination.
  • Antenna and amplifier wires: The antenna wire is blue, while the blue wire with stripes is for the amplifier.
  • Speaker wires: there are four stereo wires in total; gray, white, purple, and green. Each one of them has two variants; solid and striped. The solid gray connects to the positive terminal of the front right speaker, while the striped gray connects to the negative terminal of the same speaker. The white wire connects to the left front speaker similarly. The purple wires are for the right rear speaker, while the green one is for the left rear speaker.
car’s stereo wiring diagram

Caption: car’s stereo wiring diagram

How can you install an aftermarket stereo system without a harness?

If you fail to find a suitable radio harness for your car and the stereo, you can manually connect the stereo to the car.

First, you must keep the car’s stereo wires’ color codes in your mind.

Connect the radio cables if pigtails are coming out of the head unit.

On the other hand, if you do not have pigtails, you have two options.

Get a suitable pigtail or connect the pins to the head unit directly.

You may need a wiring diagram on the head unit for the direct connection, i.e., without a pigtail.

You can also get this diagram through online sources.


You will need an aftermarket wiring harness to install a new car stereo that easily clips to the factory harness left there after removing the factory radio.

It is essential to note the car’s year, make, and model to select the suitable wiring harness adapter.

If you cannot access that, get customized OEM wire harnesses, which must be suitable for the head unit and the stereo to make the system functional.

Cloom can help you get the best quality and the type of wiring harnesses that suit all your needs. 

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