How to Wire a Car Stereo from Scratch?

How to Wire a Car Stereo from Scratch?
How to Wire a Car Stereo from Scratch

How to Wire a Car Stereo from Scratch?

Last month one of my close friends bought a new Toyota car. I had the chance to travel with him, the car was nice but the music quality was rubbish. I checked his car audio system and I realized that the factory fitted head unit was not up to the mark.

Nowadays, it is a common problem with new cars. Manufacturers do not care about sound quality and audio equipment. I told my friend to replace the car head unit for better sound and music.

He was not familiar with replacing car stereo, he bought the new car head unit and he was confused about the installation process. He asked me, about the methods for wiring a car stereo.

In this article, our editors have explained the entire process of installing and wiring a new car stereo from scratch.

Steps for wiring car stereo Procedure
Step 1 Disconnect the battery. 
Step 2 The first step is to remove the old car stereo, remove the wiring harness, you can use Din tools for this. Remove wires connecting with the power and speakers.
Step 3 Attach the new wires connections, use tools for this. Secure all the wires by properly wrapping them.
Step 4 Test the car stereo, reconnect the battery, and play audio. 
Step 5 Properly secure the car stereo. Check the audio and you are good to go.

Whenever you are installing a new car stereo, it’s really like you are giving new life to your car. Disconnect the battery, you have to pull out the old head unit and you have to work the wiring. Replacing a car stereo might be an annoying task and you must have to do it with patience.

How to Wire a Car Stereo from Scratch?

Before installing a new car stereo, you first have to do some research on your car because there are different types of car stereo available according to car types.

You can replace a single Din car stereo with a single Din stereo only. However, if your car has a double Din stereo installed, then you can either replace it with a single Din stereo or even a Double Din Car Stereo.

You are going to do two major tasks

  1. Removing the old car stereo
  2. Installing a new car stereo

If you are doing this by yourself then must follow my instructions step by step .it may be an annoying task but you have to work carefully and follow the steps.

Tools required to Wire a Car Stereo

Before doing anything first you have to collect the tools required for your job. Eventually, I figured out that there is a proper tool for every job whether you are professional; installer or you are doing this for the first time, you must have the following tools that will help you to save your time and energy

  • Crimpers
  • Wire strippers
  • Digital multimeter
  • Soldering iron or butt connector(which you feel better or easy for you)
  • Speaker tester or 9-volt battery
  • Some type of tape that will help you in wire management and wire harness from rattling in the dash

A step-by-step guide to Wire a Car Stereo from Scratch

Here is a step by step guideline .read each step carefully and act not work in a hurry, focus on your job

Removal of a wiring harness

Take a good look at your old stereo head unit. start from removing the wiring harness. It’s good if you have a wiring adaptor it will help you to connect your new car stereo to the car’s existing clip. Wire adaptor will reduce or minimize the mistakes in wiring a new car stereo.

Car adaptor is not the necessary thing if you have a wiring harness clip adaptor then its good but if do not have any then also it’s ok. Cut the stereo wires one by one .when you cut the multiple wires at once, your power circuit may sort up and blow the fuse. When you are going to cut the wires in the factory harness

There are two types of stereo wires, first coming from your car and the second coming from your car stereo. Keep in   mind that when you are going to cut wires from the car’s harness clip from the backside, at the spot connect the corresponding wire to the car stereo otherwise you will get confused

Proper knowledge about Car Stereo Wire Connections

Power wire which is usually red in color. You have to connect the red wire coming from the car’s stereo to the red wire coming from the car. This is important that you know details for wiring a car stereo from scratch.

Ground wire: usually most of the cars come with ground wire and mostly black in color and also the ground wire coming from the car case if there is no ground wire secure ground cable to bare metal in the body.

Constant power wire: there is a 12-volt constant power wire, it can be yellow but from the car side, there may be the numbers of colors coming from the car.

Speaker’s wire: there is also a speaker wire

Antenna wire: it is a thicker wire having a metal-head at one side, before installing a car stereo, you have to connect it separately

Output converter

For the proper working of components, some cars require an output converter. Most of the time, there is a factory-installed output converter with your car stereo but sometimes you have to buy it from the auto parts or some electronic stores.

Always use output converter specified for your car for your specific model

Disconnect battery

You are going to work on the electrical system of your and there is a chance of electric shock so before starting connections of wires, first, disconnect the battery. If you do not disconnect the battery, it may harm your electrical system and can also harm you.

Whenever you start wiring a car stereo, you must first disconnect the battery before starting the procedure.

Batteries can be present under the hood or trunk you just have to lose the black cable from the negative terminal of your battery. Lose the bolt and pull cable loosen black cable put the cable down to the side of the battery so that it does not disturb you.

Wrapping all connected wires to secure them

Once you checked all the wires, and then connect them with the car very carefully. It’s better to make the connections permanent. There should be no bare wire in your car stereo otherwise it will harm you. Wrap all the wire connections with some tape.

There are some other ways by which you can wrap wires but with tape is the most common is the easy way of all.

When you are connecting two wires, it requires solder or soldering wire .for that, first melt the solder, place melted solder onto the two-wire connections and wait until it cools down and sticks properly to the wire connections.

Now it becomes a permanent bond and after that wraps the connection with some tape. Connectors are also available in the market .you just have to put both wires into it and twist them with your fingers.

Testing of car stereo

Once you have made the connections and secure them properly, first reconnect you are your battery and then reinstall your car stereo. Once you reconnect your car battery, turn on the car, and check if it is working properly. If the car is working properly, install car stereo .check one by one car speakers, cd players, and your radio.

If something is not working properly then it means that your wires are not connected properly. Review the wires connections and make sure all the wires are connected properly and if not, then disconnect the battery and reconnect the wires and again repeat the same above procedure.

Place the wires harness into the dashboard

Once you are sure that all the connections are correct and are working properly then the next step is putting all the extra wires into the dashboard. Wait have you connect the car stereo antenna wire? If yet you did not connect the antenna wire then connect it.

The antenna wire is a small wire .once you put all the wires in the dashboard, never pull any wire from the backside of the car stereo.

Placing the car stereo in its place

There is an opening in the center console of the car, it’s the place for your radio. Pick up the stereo and place it in its position. While sliding the stereo to its position, never apply pressure and if it is showing any resistance, then slide it slowly but avoid putting pressure.

You may require an adaptor to slide properly the car stereo in its right place. You can buy the adaptor from the auto parts store or any electronic store

Fixing the car stereo

There are two methods used to secure a car stereo. First, are those who require spring clips and when the car stereo locks at the right position they become lock and a click sound is produced.

The others bolts and brackets .you have to fix these bolts and brackets at the exact place from where you have removed. Fix them tightly and secure your car stereo.

Installation of the rim

This is the last step reinstall each piece of the plastic clips in exactly the reverse order you removed .do this carefully to avoid any breakage of the plastic parts. While reinstalling the rim, make sure you are doing this in exactly the reverse order you remove them. First install the last piece you removed first, check if overlapped pieces layered properly.

If some plastic part has been broken from the trim, try to secure them by the use of hot glue .here is a drawback of using the hot glue .by the use of hot glue, the plastic parts will get fixed and it becomes difficult to remove them in future.

If an entire piece of the rim has been broken completely, then the last option is to buy a new one from the market.

How you can test car stereo wires for their right connections?

I will describe one by one each wire test .follow me

Constant wire: this wire comes all the time with 12 volts .for test it, first off your ignition. First ground the black wire .pick up the red meter probe and connector touch it with the yellow constant wire. The constant wire will give the reading up to 12 volts with 0.5 difference.

Ground wire: once you have identified the constant wire, you now become able to identify the ground one. The ground wire will be connected to the black wire after proper testing.

There are two color meter probes black and red. First, you have to attach a red meter probe with constant wire and a black meter probe with the wire you are testing. Check the reading on the meter if it’s the same as for the constant wire testing, then surely it’s the ground wire

Accessory Power: when you turn off the ignition, this wire shows a zero volt reading at a meter and when you turn on the ignition it will show a reading 12volts 0.5 volts

Speaker wire: things require to test speaker wires are multimeter and a 9-volt battery before testing set a digital multimeter to resistance.

Car Stereo Wire Colors Codes

It is very important to have proper and full awareness about wire colors .each color plays a role of code. With the color of the wire, you can identify the function of each wire.

Here is a chart by which you will be better able to understand the function of car stereo wires with reference to the color.

Wire color Function
Red It’s a power wire usually
Yellow Constant retains memory for or clock
black Ground wire
Orange Illumination wire
White/blue Amplifier wire
Grey Front right speaker wire
Green Left speaker wire

Important note: different manufacturers use different color codes, the above-described color codes are not the universal ones but this above table is made by keeping in mind the majority of the cable’s color code. Most of the time it is true but not always. I have also explained the procedure by which you can test the car stereo wires.

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