Knowing how to install a car radio (stereo), perhaps, goes under a more complicated category of car DIY.
Many car owners are reluctant to do it since it involves tampering with the car’s electric installation and, in some cases, taking off easy-to-damage-plastic trim around the radio.
But as you’ll see, it’s not that tough of a job. Of course, some experience around the car will come in handy but you should be able to manage without it.
This article is not about a specific type of radio, it’s rather an explanation of the basic principle of removing and installing, whatever car radio system you might encounter.
BASIC TYPES OF CAR RADIO [CAR STEREO] SYSTEMS THAT YOU’LL ENCOUNTER
Basically two types of car radio systems:
1. Factory car radio
These are made and designed together with the car making it a perfect match, be it a classical car stereo system or a modern infotainment one. Came with the car from the factory.
2. Aftermarket car stereo and infotainment systems
Built-in afterward for various reasons (no car radio in the first place, as a replacement, etc.).
BASIC TYPES OF A CAR RADIO [CAR STEREO] INSTALLATION
Two types of installation that you’ll encounter:
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Predefined installation (with a wiring harness connector).
This is when everything is laid out for you. You have a wiring harness connector, radio mounting, etc. Essentially a plug-in plug-out job + pulling/inserting the radio.
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Installation without a wiring harness connector
The difference here is that you’ll have to connect the wires yourself. More complicated and this is mainly what all the fuss is about when installing a car radio.
More on these two types of installation lower in the article.
SAFETY AND PRECAUTION MEASURES YOU SHOULD KNOW BEFORE STARTING.
Before starting, have in mind safety.
You’re going to work around electricity and that can be tricky if you’re not careful.
Don’t be reluctant, it’s not nuclear physics; just pay attention to what you’re doing.
This mainly goes for accidentally causing a short-circuit or miss-connecting the wires.
Safety measures you should apply before starting:
1. Cut off the power supply.
Either take off the battery terminal (preferably “-“ (minus)) or pull out the car radio fuse.
This way you’ll be 100% percent safe if something goes wrong (mainly a short-circuit).
If you have problems with the fuse part, click here to read a separate article on that subject or even better watch our video tutorial on YouTube
I’d advise a combination of these two methods for better safety.
Pull out the fuse and loosen (not take off) the battery terminal.
Pulling out the fuse powers down only the line for the radio, not the whole car.
On the other hand, if anything goes really sour, you can easily remove the battery terminal and get out of harm’s way.
2. Study the wiring diagram.
Take some time and gain a clear knowledge of what you’re supposed to do. A wrong connection can cause a short-circuit, damage the car stereo or it won’t work properly.
This isn’t obligatory if you have a wire harness connector installed as the wiring installation is predefined (plug-in, plug-out system).
The wiring diagram is better seen lower in the article.
3. Watch the wiring loom when returning the car radio back in place.
Make sure that the wiring loom behind the car radio isn’t pinched or damaged when inserting the radio back in place.
It should properly fit into the empty “pocket” at the back of the radio.
This is one of the most common causes of radio installation mishaps. Best hold the wiring with one hand while inserting the radio and just tuck the wire loom into place.
4. Insulate wires carefully.
Unless you’re using plastic connectors with insulators on them, don’t spare on the insulation tape. This is mainly when you’re installing a car radio without a wiring harness connector. Once you’ve wrapped two wires together, go over the connection twice with the tape and make sure that no part of the wire stays “naked”.
5. Have the radio access code at hand.
Almost all car radios have an access code. Once you cut off the power supply, the code kicks in. This is meant as an anti-theft measure.
This goes double if you’re installing a factory car radio [car stereo]. These always ask for a code.
Anyway, don’t be surprised, once you connect the car radio, that it asks for the access code.
You can find more tips on this topic lower in the article.
WHAT TOOLS WILL YOU NEED?
One car intervention that isn’t needy concerning tools.
Most of them you probably already have around your household.
If you have a wiring harness connector on your car installation you’ll need:
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A basic set of tools
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Stereo removal tools-keys(for your type of radio)
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Plastic trim tools (mostly for factory car radios)
If you don’t have a wire harness connector and have to do some “wiring” yourself you’ll additionally need:
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Basic “pencil type” installation tester: watch the proper voltage 12V for cars, 24V for trucks
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Multi-meter: the basic type will do
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Insulation tape or plastic connectors with insulation on them
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Cutting pliers
Note: use either a tester or a multi-meter. No need for both.
HOW TO PULL OUT A CAR RADIO [CAR STEREO]?
Once you’ve prepared everything, pulling out the car radio [stereo} is next.
Car radios, in most cases, are held in place with a clip system which is behind the front mask.
Once you insert the car radio in the slot, the clips spread inside the mounting, holding the radio tightly in place.
On this part, you’ll need these:
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Radio removal tools (keys) specially made for this task. There are different types, see which ones fit for your car radio.
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Plastic trim tools: if the car has a factory radio, chances are that it will have plastic trimming around it. You have to remove them to gain access to the screws that hold the radio and mounting in place.
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Patience (essential if you haven’t done this before). Take your time and don’t lose your temper.
Now for the procedure:
1. Take out the car radio fuse and loosen the battery terminal. 
2. Take off any plastic trimming around the radio (this goes mostly for factory radios). Use plastic trimming tools.
3. If you have an aftermarket one, take the display off and the plastic trim around it. This is for gaining access to push in the radio removal keys or to screws that hold the radio in place.
4. Insert the radio removal tools (keys) into both slots (holes).
5. Insert both sides before pulling out the car radio as much as possible.
6. Use the radio removal keys as handles and pull the radio out. If possible, avoid pulling the radio by the front mask o avoid damage.
7. Pull out until the wiring appears. Disconnect the wiring harness connector, antenna connection, or any other connection that may be.
If there isn’t a wiring harness connector or plastic connectors (the wires are wrapped and insulated with tape), carefully unwrap the tape and separate the wires. DOUBLE CHECK IN THIS CASE THAT THE POWER SUPPLY IS DISCONNECTED. OTHERWISE, YOU CAN CAUSE A SHORT CIRCUIT.
Note: if you don’t have the car radio removal keys, at the end of the article you have a simple “hack” that can help.
If you’ve done everything OK, the car radio should come out without any problems.
Patience is very important, sometimes the radio will need some pushing left to right, a bit of a budge or else.
If you have to use excessive force, then you’re probably doing something wrong and should re-check the whole procedure.
HOW TO INSTALL A CAR RADIO [CAR STEREO] WITH WIRING HARNESS?
The wire harness is essentially a plastic plug that consolidates all of the cables needed for the proper functioning of a car radio (power supply, speakers, etc).
There can be one or multiple wiring harness connectors coming from the car installation.
The purpose of these connectors is to make the car radio a plug-in appliance (just like home appliances) making life easier when installing, removing, or replacing the car radio.
Also, thanks to standardizing, almost all wiring harnesses are compatible with every car radio.
For instance, if you buy any kind of aftermarket car radio, there is a good possibility that it will fit the installation on your car. How good is that?
Even if it doesn’t (for instance speaker arrangement or else), you can change the pins inside the harness and solve the problem.
To get back to the procedure:
1. Connect the new car radio. Take a look, just in case, that the harness is the same and that it fits into the slot of the radio. Don’t worry, the plastic plug has such a shape that it can be connected in just one way so you can’t make a mistake.
2. Connect the other installation ( antenna, CD changer, a multimedia device, or else).
3. Before inserting the radio back into place, return the power (fuse or battery terminal) and try the radio out. See that everything works. This way, if something’s wrong, you can check it out and avoid another removal.
4. Insert the wire harness into the hole in the console, sort of tuck in the wiring loom. Make sure that the harness will not be pinched or damaged.
5. Insert the radio back in place.
6. Make sure you hear a “click” sound. That’s a sure sign that the holding clips fell into place and that the radio sat in properly.
7. Turn on the car radio and see, again if everything is OK.
HOW TO INSTALL CAR RADIO [STEREO] WITHOUT WIRING HARNESS?
As mentioned, most car electric installations have a built-in wiring harness for connecting the car radio.
But because of various situations (previous DIY installing, different types of radio, etc.), the wire harness may be missing.
You’ll find yourself in a situation where you simply don’t have a plug for the car radio.
But there is a solution to this:
- If you have a radio with a standard slot(s) for a wiring harness connector, go to your local car parts shop and buy a new wire harness connector that fits.
Your task will be to connect the harness to the car installation making a plug-in connection of your own
- If you have a radio without a wire harness connection (wires directly coming out of it), directly connect the radio wires to the car installation (wrapping the wires, insulating with tape, etc).
Mostly, when you buy a new car radio it will have included the wiring harness connector, with used ones you’re probably going to have to visit the car parts shop.
So, once you’ve solved the missing wiring harness connector problem, you’re good to go on connecting it to the car installation.
To resume on this part: you’re connecting the wire harness connector to the installation, not the car radio. Imagine this as installing an electric plug on a home appliance. Simple as that.
The car radio is plugged in afterward.
Before you start, have in mind that the car installation should have (as a standard) all of the needed elements (power supply, ground, wires for the speakers, etc.).
Your job is to merge that installation with the new wiring harness connector.
Before you start, take a look at this basic wiring diagram. It should give you a good idea about what is what and about the connections:
The color of the wires is standardized on most cars so this should also help you.
Also, click here for an additional great explanation on Wikipedia.
Use the colors of the cables to help you get a proper match.
Here’s the procedure:
1. Pull out the wiring from the hole in the console. They should be long enough for you to work around them.
2. Separate the wires apart so you don’t accidentally cause a short-circuit.
3. Use the pliers or a scalpel to take off some insulation on the end of the cables (1 cm max).
4. Use the tester to check the voltage supply and ground. This is for precaution and in case the colors of the cables are different from standard. This way you’ll avoid miss-connection or even a short-circuit (like connecting “+” to “-“).
Also enables you to choose a power supply, either the car radio will work only with ignition on or when it’s off.
5. Work out the speaker cables, where goes where. If you have a problem with this, there’s a simple “hack” near the end of the article that should help.
6. Start connecting the cables. Wrap the wires together very tightly, good contact is crucial. If you have the means and will, solder the connection together. This is great for contact.
7. Insulate the connections with tape. Go around two times; good insulation is also crucial so you don’t accidentally make a short-circuit when returning the car radio.
8. Before inserting the radio back in to place, return the power (fuse or battery terminal) and try the radio out. See that everything works. This way, if something’s wrong, you can check it out and avoid another removal.
9. Insert the wire harness into the hole in the console, sort of tuck in the wiring loom. Also, try to make a solid wire loom with insulation tape. This is preferable so that the wires don’t get all over the place when returning the car radio.
10. Insert the radio back in place.
11. Make sure you hear a “click” sound. That’s a sure sign that the holding clips fell into place and that the radio sat in properly.
12. Turn on the car radio and see, again if everything is OK.
Check every radio setting, mainly the speaker settings (balance) so that you know that you haven’t cross-connected them.
If the power supply is connected to the ignition, turn the ignition off and see that the radio also turns off.
HOW TO INSTALL A CAR RADIO[STEREO] MOUNTING?
Installing a different car radio mounting is pretty rare.
Mostly happens if you accidentally break the original, want to install a different type of car radio, or want to replace the classic stereo system with an infotainment one.
Two basic types available:
- Specifically for your car model: same as the original, molded to the looks of the console, perfect fit in terms of installing
- Universal mountings: looks like a sleeve for the radio, has perforations on the sides meant for bending into place (for attaching the mounting to the console).
Replacing the mounting is a very easy job, the basic procedure is:
1. Follow the upper mentioned radio removal procedure.
2. Once the car radio is out you’ll find screws holding the mounting.
3. Unscrew them and pull out the old mounting
4. Insert the new one and tighten the screws.
5. If you’re installing the metal universal one, push it in place and bend the side perforations. There are lots of them, just bend them in so the mounting has a firm grip on the console.
That’s pretty much it, a simple replacement job.
I would advise, on this part: if possible, always buy the mounting specifically for your car. This goes double if you’re changing a classic car stereo system with infotainment.
In today’s spare parts market, you can find these mounting for almost all cars and they are not that expensive.
The end result will be a perfect fit and you won’t notice the difference between factory installment and your own.
Universal metal ones are best for classic and basic aftermarket car radios (you know, the ones with a 90’s look display, USB connection, and maybe a Bluetooth connection).
DIY should be avoided, in my opinion since it involves in most cases drilling, filing, cutting around.
The end result, to say the least, can be unsatisfying. Besides that, the amount of effort and time needed to do this doesn’t justify the small cost of an original mounting.
HOW TO DECODE A CAR RADIO [CAR STEREO]; IF YOU’VE LOST THE CODE OR DIDN’T HAVE IT IN THE FIRST PLACE?
Once you successfully connect the car radio, most will ask for an access code (factory radios especially).
The lack of this code has thrown many people into despair. Understandable, I mean you did the whole installation thing successfully, and then: BOOM! If you don’t have the code it’s all for nothing.
This is also from my own experience so here are a few useful tips that I hope will help:
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If you’ve bought the car new or from a licensed dealership, the radio code should be in the user’s manual or in the service (maintenance) booklet. Search for a 4 digit number (in most cases).
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Contact the licensed dealership, if the car was bought new, they should be able to give you the code. Ask, it doesn’t hurt.
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If the car is used (which was my case), try contacting the previous owner (especially if he/she was the first owner). They’re bound to have the number somewhere around the house.
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In some cases, take the radio out of the console and search for the number sticker on the side of the radio. I know it sounds a bit stupid, but nevertheless is a common solution.
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If all of these solutions fail, simply take out the radio and take it to a specialized radio shop. Explain what happened (so nobody thinks you’ve stolen it) and they should be able to help you.
Once you’ve got the code, the most usual way of typing in the code is with the buttons on the car radio.
Most common system:
First digit=first number, second digit=second number etc.
The number of times you press is the wanted digit (4 presses=number 4).
Best prepare yourself and don’t start the car radio removing/installing before you find or get reach of the access code.
Spares a lot of time and nerves later.
HOW TO CHECK IF THE SPEAKERS ARE WORKING AND FIND THE RIGHT CONNECTION?
This part is an extra and I couldn’t help but share it with you.
Sort of a hack and comes in handy if the speaker wiring is mixed up.
For this situation there are various reasons:
- Someone before you probably tampered with the wiring, cutting the original colored wires off and extending them with different colors
- Wiring installation, for some reason, isn’t standard
- Connection on the speakers are tampered with
A list of possible reasons goes on.
Once faced with this, you can end up losing lots of time figuring what wire is for what speaker.
For this “investigation” all you’ll need is a 12V battery and perhaps, some paper tape.
Here’s the procedure:
1. Pull out all of the speaker wires and separate them.
2. Remove the insulation from the top of the cables.
3. Take two that you suspect may be a pair for one speaker.
4. Connect both wires to the “+” and “-“ends of the battery.
5. If you’ve found the correct pair, you’ll hear the speaker; it will make a faint crunchy sound.
6. If you’ve missed you’ll hear nothing.
7. Go around every wire. Use the tape for marking the wires, wrap it around every cable so you know what wire is for what speaker.
This is a simple elimination process that’s helped me lots of times and I hope it will do the same for you.
No fancy tools, no extra expense, just a simple battery, and some time and patience.
HOW TO MAKE YOUR OWN CAR RADIO REMOVAL TOOLS (KEYS)?
If by any chance you don’t have the possibility of buying car radio removal tools, there is a solution.
This is also somewhat of a hack, but I think it’s worth sharing.
Goes for car radios that use the wire-like removal tools, not the flat, sheet-like, ones.
All you need is some wire. Preferably copper one as it is easily worked with. Steel wire will also do but is harder to bend.
Copper wires are easily found in home installation cables, find one that has full section wires in it.
Next, you should:
- Cut a piece of cable, about 20 cm in length.
- Peel off the outer insulation of the cable and pull out the wires. Use pliers or a scalpel
- Pull out two wires
- Peel the insulation off at both ends of the wire
- Bend the wire in such a manner that you form a fork (you’re making a copy of the original tools).
- Insert the forks into the front end of the radio and you should be able to pull the radio out.
Perhaps they won’t “stick” on the radio as the original tools do, but it should help do the job.
Also, adjust the width and length of the tool according to your car radio.
In the last picture, although done on an older type of radio, you can best see how it all works in practice.
