Installing Aftermarket Head Units

Upgrading the sound system is usually one of the first modifications attempted when we talk about car customization. The best place to start is with a good head unit. If you plan to install it yourself, read on for some technical tips from our experience installers.

You will need a few tools to do the job right, so start by collecting some screwdrivers (flat head and phillips head), a socket set, wire cutters, wire splitters, butt connectors or heat shrinking sleeves, electrical tape, zip ties, solder and a soldering iron, and some patience.

The first thing I would do before installing I would suggest buying the stereo wiring harness for your vehicle application. This will make the installation easier for you if you are a beginner, and it allows for easier replacement of the stock radio (if you choose to sell the vehicle in the future) and swapping or upgrading to a different aftermarket head unit.

Begin by disconnecting the negative battery cable from the battery. This will ensure that you do not accidentally cross any wires and burn out a new piece of equipment. Next, remove the old head unit. If you need to see how this is done on your specific vehicle, you can look up your vehicles application on This is a great resource for seeing pictures of how to remove the head unit. Once it is loose, disconnect the wiring harness and the antenna from the head unit and remove it completely.

There are two types of wiring harnesses you can get. There is the universal wiring harness that connects to your vehicles existing wiring harness, and has the unfinished wire ends that connect to the color coded wires of your new head unit. There is also a wiring harness that has a harness on both ends, and just clicks in place on both sides. These are the easiest to install, but can be harder ot find to match your vehicle to the head unit. Most wiring harnesses are the universal type, so we will focus on those. If you have obtained the wiring harness, you will notice the color coded wires in the back of the head unit. The wires on the head unit and wiring harness should match. The head unit wires and the wiring harness wires will be partially spliced ​​for easy installation. There are several good ways to connect the wires. One way is to use butt connectors, which crimp the wires within a connector. These can be picked up almost anywhere that sells / installs head units, or at Walmart, etc. My favorite way requires a soldering iron and heat shrinking sleeves. Twist the wires together tightly. Apply just enough solder to weld the two wires together. Now fold them over parallel to one of the wires. Slide the sleeve over the connection and heat it with a heat gun or good hair dryer. I have had to rewire or repair systems where butt connectors were used, but this could be installer error, and not a problem with the connectors themselves. I have never had any of the soldered connections fail.

Once all the connections are made, and the sleeves heated and shrunk in place, I like to take a zip tie and tie them all together. Clip the excess zip tie for a clean finished look. Connect the wiring harness of the head unit to the wiring harness connected to the vehicle. Plug in the antenna (you may find you need an antenna adapter in some applications). Now slide the head unit in place, but do not attach it yet. Reconnect the negative battery cable and turn on the head unit (make sure the key is turned to the ACC position). It should be functioning properly at this point. If you plan on adding an amp, or have purchased one for this setup, turn the unit off and connect the RCA cables. Run them through the dash to the floorboard and to the amp (more on how to successfully do this in future articles).