Contact us
Close contact box
Connect ID #
406 910 757 4
Connect ID #
406 910 757 4
Don't wait on hold. We'll call you back when it's your turn to talk with the next available .
Please enter your name  
Please enter your phone number  
Please enter a message  

Calls may be recorded for training and quality control purposes.

We are located in Virginia USA.

Thank you. We will be calling you .
We're sorry. We have encountered a problem.

How to connect your new car stereo's wiring

Be sure your wire connections are solid

Installing a new stereo starts with connecting all the wires. There are good ways and bad ways to do the wiring. In this article, we'll show you how solder, tap, and crimp all the wires to ensure that your new stereo works right the first time.

The first step to installing a new car stereo is connecting the stereo's wiring harness to the adapter that will plug into your car. Making long-lasting, secure wire connections is of the utmost importance. By using one or more of the methods illustrated below, you can be sure that your connections will last for years to come—and that your new car stereo will work properly.

How to connect two wires

Most of your connections will require splicing the ends of two wires together. About a dozen times over. Below are what we consider to be the best ways to do this. Use the method that works best for you.

Soldering two wires

Soldering makes the most solid connection. Heat shrink tubing protects and insulates that connection. The task always starts with a wire stripper for removing insulation from the wire ends.

Using Posi-Products connectors

Posi-Products™ connectors are easy to attach and stay firmly in place. This is our favorite method because of the quality of the connectors and the simplicity of the technique.

Crimping wires

Crimping can create a reasonably solid connection. You'll need a crimping tool and crimp caps. The only potential drawback is that if the caps aren't crimped tight enough, they can shake loose. Give them a good tug before you install that stereo!

How to tap into existing wires

Sometimes you need to connect a new wire to the middle of an existing wire. This is called "tapping" the wire, and there are several different ways to safely and securely do it. Here are our three preferred methods. Your situation will help determine the best way to do it.

Tapping with Posi-Tap connectors

Just like their wire connectors, Posi-Tap connectors are easy to use to create a secure tap into another wire.

Tapping by soldering

Soldering is the old-school way to get the job done, and here's the trick for properly soldering a tapped connection.

Tapping with a T-splice (no solder)

T-splicing, also referred to as a "mechanical" splice, is the way to create a solid connection using only the wires themselves. Sometimes it's the only way to get the job done. It's also a good option to practice on a workbench.

Let us do it for you — Crutchfield ReadyHarness

For most cars, we offer the Crutchfield ReadyHarness™ service. We will take the harness from your new stereo and your vehicle specific adapter harness and professionally connect the two before we ship your new stereo. We'll let you know if this service is available for your car when you tell us what you drive and select a new stereo.

Crutchfield ReadyHarness

Meanwhile, you can learn more about the process in our ReadyHarness article. Keep in mind, you might still have to tap into a couple of wires in your car — we can't do that part in advance.

Install it like a pro

Facing those two bunches of wires can be intimidating, especially if this is your first installation. But the task really isn't that hard if you take your time and make your connections with care, one wire at a time. Before you know it, you'll have your new stereo installed and ready to rock.

If you run into a problem or get stuck – and if you purchased your gear from Crutchfield – give us a call and our tech support team will walk you through it.

  • Joseph Stall from Cville,TN

    Posted on 7/6/2023

    Hello - I am installing the JVC KW660BT into a 2017 Ford E450 based Motorhome. I followed the instructions given with my purchase. With the JVC, 2 wire adapters were included. I spliced both of them to the 70-5520 connector that you sent me. These 2 adaptors connect into the JVC KW660BT. So I have a JVC radio with the 2 included adapters from JVC, which plug into the JVC, spliced to the big 70-5520 as the new harness. When I remove the radio from the dash, there is one big connector that connects to the 70-5520 and then another connector. In other words, the old radio has 2 connectors, a big one and a small one. The big one is accounted for with the new wiring harness. What about the second connection out of the old radio? What do I do with that? Am I missing something here, like another connector?? Thanks

  • Joe

    Posted on 6/21/2023

    Very disappointed in crutchfield i thought i could purchase the harnesses that would make it easy to change stereo in my mach 460 sound system. Info showing me how to twist wires together though thank you.

  • Gunnar Stevens

    Posted on 5/15/2023

    I was very disappointed to see that your Ready Harness service was using cheap auto parts store crimp fittings. I expected more from you. I'll most likely cut out the crimp fitting section of the harness and solder the fresh wire ends back together. I would think that since your videos on connecting wires feature three different methods and stating that soldering them then covering with shrink fit tubing is the best method that that would be the method employed. Your videos don't even address the method that you use which is prone to failure! Again I'm really disappointed and feel that my $25 was wasted.

  • James from Kingman

    Posted on 4/21/2023

    Don't get any sound

  • Mark

    Posted on 3/2/2023

    I paid for ready harness service yet I have to crimp wires - I thought that was supposed to be done for me. I cannot get the plastic coating to slide off of the reverse or Steering wheel remote input wires... ugh!

  • Bruce Vinal from Townsend

    Posted on 12/8/2022

    Got 4 pages telling me how to take the dash apart then basically "connect wires" even with the ready harness it's a nightmare. Help line was responsive and as helpful as they could be but I don't know enough about what I don't know to know what to ask.

  • Rowdy L Twogood from Colfax

    Posted on 11/12/2022

    I cannot figure out this parking brake thing with this stereo I cannot access anything on it. I really don't like the design the stereo sounds great but the parking brake things kind of stupid if I can't figure it out can I trade it in if I can't get it figured out

  • John Steinebach from Ontario Oregon

    Posted on 2/23/2022

    Great videos and information thank you

  • Jason Sallee from Grand Junction

    Posted on 1/2/2022

    Where is the video on how to hook up the extra wires like for your parking break and speed sensor for example?

  • Mike Christy from Elk Grove

    Posted on 10/2/2021

    I really like the videos, with one exception. The way the electrical tape is torn will promote it peeling away much sooner. If you cut it without stretching it, it will stay in its normal shape and adhere to your wires much longer. On a seperate side note, if your wires are going through a wall or near heat, Tessa tape is a great insulator.

Looking for
car audio installation tools?

Car Audio Installation Tools Shop our selection

Find what Fits your vehicle


Checking fit...

Compare the sound