A guide to car stereo wiring harnesses

Getting a handle on all those wires


Dave Delamere

Dave was born in Buffalo, NY, but spent the majority of his life in central and northern Virginia. He began his collegiate career at Virginia Tech, but completed my education with a degree in teaching from Radford University. His Crutchfield career began in 1997 as a Sales Advisor. His father had been a satisfied Crutchfield customer since the '80s, and when Dave saw the job opening, he knew it could be a good thing. In 2013, the Crutchfield creative staff grew tired of the corrections and suggestions Dave always threw their way, so they decided to give bring him on as a copywriter for the mobile electronics division.

When not dealing with these corrections and suggestions, Dave enjoys watching and playing ice hockey. Cooking intrigues him, although cleaning up after does not. Movies, music, and art take him away. Crime and forensic shows bring him back. History makes him pause. His interest in electronics stems from fond memories of making mix tapes from vinyl, radio, and the newest format at the time, the compact disc.

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While they can look like some sort of multicolor pasta dish, wiring harnesses help you connect your new car stereo to your vehicle's wiring. In this article, we'll explain the different types of harnesses and adapters that Crutchfield offers and how they're helpful when installing your new car stereo.

We'll also touch on some of the other types of adapters that might be needed for installing other audio gear.

Car stereo wiring harnesses

Each vehicle has a different wiring story. Sometimes you have a choice of harnesses that will work in your car. Other times, you might need more than one harness to complete the installation. Our customers often refer to these as "Crutchfield wiring harnesses," but the fact is that they come from several different manufacturers. We just try to make sure you get the one you need when you shop with us.

Metra 70-8901 Receiver wiring harness, usually includes a wiring diagram

The basic wiring harness

These represent the most common type of wiring harnesses. They offer connections for the power and speaker wires. They can also include connections for the new stereo's ground and illumination wires.

Using the wiring diagram the adapter manufacturer supplies, these harnesses enable you to match up the wires for each connection to the new stereo's wiring harness. Once that's done, you plug the other end of the harness into your car's wiring connector (the one that was plugged into the factory radio). Using your car's factory stereo plug wiring connector is the key to installing a new stereo without damaging your vehicle's electronics, especially in modern vehicles, which we'll discuss next.

Specialized wiring harnesses

Vehicle audio systems, electrical systems, and convenience features have come a long way. So, the harnesses had to evolve to handle the complex wiring and data information that modern cars use.

Connections at a distant location

In some vehicles, you need to plug in the harness somewhere other than behind the radio. A great example is a common version of the Ford Taurus, where the factory amp and radio tuner are located in the vehicle's trunk. These harnesses often consist of a basic wiring scheme that has wires long enough to reach the necessary destination. In the case of the Taurus, the adapter includes 20' of speaker wire to reach the trunk.

Hook up your new radio by bypassing the factory amp

A vehicle's stereo system sometimes has a separate amplifier, and when installing a new receiver, you generally need to connect the new stereo's speaker wires to the factory amp's output section. These amp bypass harnesses allow you to use the power from the new car stereo to drive your speakers and not rely on factory power.

These harnesses tend to be more affordable than amplifier integration adapters (below), but can involve more work if the amplifier is in a remote location, like under a seat or in the trunk.

Scosche CNN03 wiring harness

Factory amplifier integration harnesses can include gain controls to reduce distortion.

Keep the factory amp in play

Many wiring harnesses can let you keep your vehicle's factory amplifier when replacing the stock radio. They include connections that directly tie the outputs of your new car stereo into the factory amplifier's inputs. So, you'll be using the factory power for your speakers, instead of the power from your new radio.

These harnesses can sometimes shorten the installation time, since wires often do not have to be run to the factory amplifier location, but they tend to be more expensive than the bypass harnesses above. You may also see a module connected in these harnesses — they include adjustments that enable you to properly integrate your stereo's speaker outputs and the factory amp's inputs to keep your music clear.

Retain those important audible safety alerts

In many vehicles, the audible safety alerts are integrated into the factory radio. When you replace that radio, these warning sounds are lost, and that's dangerous. Thus, these vehicles require a special harness to keep these audible tones working when you install a new stereo. Fortunately, these harnesses also take care of all of the basic stereo connections.

Hang on to factory conveniences you love

Today's cars include an ever-growing number of features built into the factory radios, which complicate wiring connections immensely. They can include things like Ford SYNC®, GM OnStar®, Chrysler Uconnect®, and steering wheel audio controls for the stereo and your phone.

When you replace the factory radio in these vehicles, a more-robust type of integration adapters is needed in order to have these features work with your new stereo.

Some integration adapters, like the iDatalink Maestro, even enable you to download programming for specific receivers and vehicles so you can keep as much of the factory functionality as possible.

Alpine KTX-FPU8 Factory Integration Adapter

This integration package includes the dash kit, connections, and brackets for a installing a stereo in a Ford F-150.

Packages that connect and secure your radio

There are also vehicles that not only have a complicated wiring scheme, but they also have a unique dash layout. Integration adapters for these vehicles include both the wiring connections and a custom dash kit to get your new receiver installed.

These generally include just about everything you need to get the receiver connected, mounted in the dash, and retain many of beneficial factory features, such as electronic climate controls.

Additional adapters for car stereo installations

Sometimes, a wiring harness won't take care of everything and you need additional adapters to install a new stereo. They can help with a specific connection or allow you to keep a factory feature.

Antenna adapters

Many factory AM/FM antenna connectors simply plug into the antenna port on the rear of a new receiver. However, some vehicles have an antenna connector with a different shape or are part of an amplified antenna system. In these cases, an antenna adapter becomes necessary for your radio installation so you can keep your AM/FM stations playing.

Steering wheel audio control adapters

Modern vehicles often include steering wheel controls to let you safely operate your factory audio system without taking your hands off the wheel. These functions include volume controls, track forward/back, and hands-free calling controls. In most cases, those controls won't work after replacing the factory radio. Thankfully, steering wheel control adapters help integrate these controls with many new stereos, so you can keep using these handy controls with your new stereo.

Learn more about these adapters in our steering wheel control adapter article.

Metra 71-012C Speaker Wiring Adapters

Speaker wiring harnesses

While they don't directly help with car stereo installations, the speaker wiring harnesses we offer let you use the factory speaker wires for your new speakers, just like car stereo harnesses. Their plugs match the factory speaker wiring plugs in the vehicle, and the other ends slide over the new speakers' terminals. That way, you don't have to run new wire from the radio to all the speaker locations in your vehicle or cut factory wires. These adapters are also free with a car speaker purchase from Crutchfield.

How do I know what I need?

We'll show you! You can use our Outfit My Car™ application or contact one of our expert advisors for help choosing the right harnesses to work with your vehicle. They can also answer any questions you have about the installation and give you some idea about how difficult it'll be — some vehicles are easier than others. You can reach them at 1-888-955-6000 or via chat or email.

Last updated November 03, 2015
  • sebrina

    Posted on 5/13/2015 10:43:46 AM

    i have a 2004 cheve Silverado we r looking how to do stereo wires diagram please help

  • Alexander Hrabe from Crutchfield

    Posted on 5/13/2015 12:54:13 PM

    Sebrina, you should be able to find what you're looking for on our tech support page. Click the blue button that reads "Search Knowledge Base" and type in your complete year/make/model information in the resulting search field. In your case you'll also need to know if your vehicle has the Bose system and/or OnStar. If you'd like a vehicle-specific wiring harness for an easier installation, just give us a call, and an advisor will be able to help you.

  • Richard Steinbach from United States

    Posted on 5/26/2015 1:57:55 PM

    I have a 2000 Dodge Durango with infinity system that I need a pigtail with the connectors that plug into the original stereo.

  • Alexander Hrabe from Crutchfield

    Posted on 5/27/2015 8:46:49 AM

    Richard, if you have a particular aftermarket stereo in mind that you'd like to integrate, the easiest thing to do is input your info in our vehicle selector and select your stereo of choice. You will be shown your options for retaining factory features. If you have any questions, just give us a call at 1.888.955.6000

  • Russ

    Posted on 6/12/2015 2:19:13 PM

    how do I install a video bypass for a AVH-4100NEX for my boat?

  • Alexander Hrabe from Crutchfield

    Posted on 6/12/2015 3:01:24 PM

    Russ, Pioneer does not disclose how to bypass the video safety feature. But they weren't thinking about boat owners. Try contacting Pioneer support at 1-800-421-1404.

  • wes from mesa, az

    Posted on 6/25/2015 6:23:27 PM

    I have a 2005 Pontiac GTO. I'm trying to find out what wiring components I need to use aftermarket radio and keep the factory amp and speakers and also steering wheel controls. Is that possible?

  • Alexander Hrabe from Crutchfield

    Posted on 6/29/2015 1:24:08 PM

    Wes. Yes, it is possible. You'll need a vehicle-specific wiring harness and a steering wheel adapter. I've passed your information on to a Crutchfield advisor, who will contact you soon to help.

  • Alec from Hooksett

    Posted on 8/7/2015 3:02:37 PM

    Hi, i have a 2006 dodge stratus, and when i attach the radio (jvc kd-r760) to the car, i can turn the car in the "on position and the radio works, turns on, i can setup settings and everything, but when i go to start it i get a wiring/fuse malfunction error code. I can re-instal my old radio and it works fine. There is a brown wire on my harness that says :mute/not used. Should i disconnect this wire, or is there another problem? I know the brown is a mute for onstar/bluetooth from what ive researched, and my car has neither. Is it a problem that my original witing does not support that wire? Help would be greatly appreciated

  • Alexander Hrabe from Crutchfield

    Posted on 8/10/2015 1:35:07 PM

    Alec, the brown wire is unrelated to your problem. The fact that the problem occurs when you turn to the ignition points me to the red ignition wire. A look at the wiring diagram in your new receiver's manual says that the red ignition wire must be wired into the car's fuse block if your factory wiring harness doesn't have a 12 volt ignition switch wire. The easier and inexpensive way to go would be to use a vehicle-specific wiring harness to connect your stereo. Give us a call, and an advisor can help you with the harnesses you'll need for a satisfying installation.

  • Nancy from Tacoma

    Posted on 8/17/2015 1:01:35 AM

    I find most of these comment not really very helpful, as I have installed many stereos and even the 99 Tahoe w/amp hook up the remote wire so the amp is powered up but I find sometimes information is left out,,, would it not be easier to remove the plug on the bottom of the amp and run a ign hot to same, as I can't get it to work...?? it should I have test the deck in another auto and all is fine, so it is in the wiring using a meter 70-1858 I thought it should be the 1859 which has a power wire for the amp?? I'm lost... If you can help please educate me... as I have the blue wire for power ant/remote hooked to the factory wire which in turns goes to pink on the back side... when I turn the car on the deck doesn't not come on but the rear amp speaker click and so does the amp... what am I not doing?? Ask 10 people get 10 answers like where is the amp mine is by the gas pedal not behind the glove box which would be better I think to get to.

  • Alexander Hrabe from Crutchfield

    Posted on 8/17/2015 11:45:15 AM

    Nancy, the pink wire triggers an amplifier relay that supplies power to the orange wire at the amp. You'll find wiring information for your vehicle in our online Knowledge Base. Using the 70-1858 harness with the eight-speaker system, you'll need to make sure that the amp remote wire on your new stereo is connected to the blue wire on the harness. If you bought your gear from Crutchfield, you can call Tech Support for free help troubleshooting your system. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Check out our tech support page for details.

  • billy pennington from Tompkinsville

    Posted on 9/5/2015 6:57:52 PM

    I have a Nissan pickup with a pioneer head unit put new speakers and wires from head unit to speakers now radio won't put out any sound

  • Alexander Hrabe from Crutchfield

    Posted on 9/8/2015 1:20:26 PM

    Billy, there are many potential causes to your problem. A good first start would be to retrace your installation steps and recheck all of your connections to make sure they are secure. Any interruption of signal from the radio to the speakers will cause them to function improperly. If you bought your gear from Crutchfield, you can call Tech Support for free help troubleshooting your system. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Check out our tech support page for details.

  • Andy from Michigan

    Posted on 9/10/2015 2:41:20 AM

    In need of wiring diagram for 2000 sable WITH climate control. I can't seem to find just a harness for a radio install. I'm not paying 180 for a dash kit but need to know the wires so I can hook up my radio. Thank you

  • Alexander Hrabe from Crutchfield

    Posted on 9/10/2015 12:45:01 PM

    Andy, you may be able to find the wiring info you need in our online Knowledge Base.

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