How to connect your new car stereo's wiring
Be sure your wire connections are solid
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 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.
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.
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
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.
James D. Grow from Plato
Posted on 9/9/2021
Purchased Jensen CDR6221, Maestro, and ready harness to replace a radio in a 2008 Honda Civic LX. Pulled old radio out and found harness didn't really match what was done by someone else. Apparently, the car had a multi-channel amplifier and mono-channel subwoofer amplifier installed previously. Had to cut off harness for new radio to install. Now, door locks won't unlock unless key is on, and radio with backup camera won't turn on. Need help. Additionally, wiring for car has extra connector that wasn't attached with other radio. Help would be greatly appreciated.
Alexander H. from Crutchfield
David Whalen from Benton
Posted on 8/3/2021
I have a 2011 kia optima and I can't find the color code for the factory harness please any help will be appreciated.