How to Install A Car Amplifier – A Comprehensive Answer

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Installing a car amplifier lets you play your music with improved audio quality. It also raises the equalizer in a way that brings out the detail in every song at any volume, either very low or high.

How to install a car amplifier
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In this article, we are going to guide you, step by step on how you can successfully install a car amplifier. But first, you have to ensure that you have purchased a good amplifier like the Pioneer GM-A6704 Car amp.

Although this is dependent on the brand and body structure of the vehicle you have, the car amplifier purchased is also a key factor.

Before You Use This Guide, You Might have to Consider the Following.

What are the accessories you will need for the installation?

Where should the amp be put?

What do you need to dismantle before you connect wires?

Accessories You Need for the Wiring

Amplifiers installed in cars usually do not come with the wiring. The owner supplies speaker wires, remote switch-on cable, inline fuse as well as the amplifier’s power wiring.

Power Wires

The power wires must be thick and good enough to accommodate the amplifier’s demand for electricity and if the current is not enough then the amp will not function properly or even power.

Your amplifier’s instructions include a recommended wire size to use during installation.

You will also measure the distances to be covered by the wiring to accurately ascertain the length of wire to use.

It is highly recommended that you read the instruction book properly to get the definite current needed for the wire connection.

A Fuse for System Protection

The fuse fixed on the power cable that is mounted within 6 inches of the connection of the car battery is important for securing the wire from causing an inferno in the car if there’s a short circuit.

Wire manufacturers rate their wire capacity using their in-house scale but for a 16-20-foot run, it’s usually safe with the following.

25-amplifier meld with 10-gauge wiring

60-amplifier meld with 8-gauge wiring

100-amplifier meld with 4-gauge wiring

250-amplifier meld with 1/0-gauge wiring

An Amp Setup Kit

The best way to get all the wiring items you need for your amplifier is to get an amp wiring kit that has a matching power, turn-on cables and fuse.

Amplifier setup kits also have speaker wires and RCA cables. Although the signal wiring is not always included, you can get your input signal from the output of the receiver routed via RCA wires.

The cables usually come in pairs and in different lengths. When you have to connect new speaker wire from the amp’s output down to the speaker, you can use any wire with a gauge of 18 to 14.

You should also know that a lower gauge number gives you a thicker wire and while installing subwoofers, you have to use 16-12-gauge wires.

Where to Mount Your Amplifier

Before you choose a good location for installing your amp, you should study your car properly to know the best location that will not obstruct any connection in the car. 

There is a manufacturer’s guide that comes with your amplifier, follow it step by step to ascertain a location that will make the installation hitch-free.

You should make sure that the amplifier is three feet away from the car stereo to prevent any external sound coming from the car’s electrical setup.

The amplifier also has the capacity to interfere with the radio reception of the stereo.

Avoid bolting your amp directly to your vehicle’s metal body as this may turn out to be causing noise from the bottom of the car.

Your best bet is to use rubber cringle around the screws to separate the case or mounting the amplifier on a board made of wood and attach it to the body of the car.

You should know that an amplifier produces heat when it is on which gets absorbed and radiated by the heatsink.

This demands that a few yards of air space be given around it to keep it cool while working.

Another error you should avoid is mounting your amplifier upside down as heat will certainly radiate back into the amplifier.

You should also make adequate provision for space to connect the wires and conveniently adjust the control buttons.

Buy this Pioneer GM-A6704 4-Channel Amplifier here

There are Good Locations You Can Install Your Amplifier and They Include:

The firewall

This is also known as the passenger’s side. The benefit of using this is that you use short wires and cords.

You connect the wires in a way that you don’t have to remove any seat.

The disadvantage here is that only small amplifiers fit into this space and to a very large extent, it exposes your amplifier to some noise sources.

The Trunk

The trunk serves you enough space especially if your amp is large and this will require long wires.

Installing your amp here will require that you sacrifice space meant for goods or other items put in the trunk.

Under the Car Seat

Another installation option is under the seat close to the amp’s receiver and this implies that you will have to use the shorter patch and signal cable which will reduce the impact of noise and signal disconnection.

It is also closer to the speakers at the front and this makes it easier for you to run wires across without worrying about the distance.

The beauty of this location is that you are not sacrificing any space meant for items or goods.

However, installing your amplifier under a car seat means that you have to detach the seat during installation, and this has the capacity of deactivating your car’s SRS system (airbag).

Video: How to Install A Car Amplifier

This video gives a step by step guide on how to install a car amplifier

Where Can I Run the Wiring for My Amplifier?

All wiring must be concealed to ensure safety and to give you a nice look after installation.

Wires used in connection should be concealed and secured to prevent interference with vehicular operation.

You should know that the wires have to be connected under the dashboard, door plate or kick panel irrespective of the location you choose to install the amplifier.

Follow the following instructions to understand the installation process putting into perspective the panels that have to be detached and they can come off.

Most times, panels are pried up to the edges. You will also have to remove certain screws and clips.

You have to be very careful while doing this so as not to damage any part of the car. A panel tool should do it for you.

How to Remove Door Scuff Plate?

The door plates can be detached by prying the edges up to release all the clips. Some cars have screws there which you will have to remove.

How to Remove the Car Seat Belt?

The car seat belt is usually screwed to a different panel that you have to remove. The seat has an anchor cover that pries off.

The anchor is usually safeguarded with a bolt and you have to unscrew it from the panel.

How To Remove The Pillar Trimpanel

If the seat belt is present, you have to remove it. Remove all plastic clips, screw covers and screws if they are present.

You should pry up all the ends of the car panel to remove it.

Search for the screws and pry out the retaining clips. You should also pry out ends of the car panel to remove it.

How to Route Your Wire on The Dashboard?

When routing your wire at the back of the dash, make sure to safeguard it with a plastic wire tie.

Ensure that the amp wire is fixed in a way that it doesn’t interfere with the operational parts of the vehicle.

This is recommended to ensure the safety of your vehicle.

Now it’s Time to Start the Installation

You don’t have to be in a hurry about the installation. Take your time to gather tools, bolts, and a soda.

You will also need a friend to give you a hand and most importantly you need enough time.

Now Here are the Installation Steps

Battery Disconnection

Park your vehicle and set the brake. Disconnect all the negative battery terminals in other to prevent electrical shocks or shorts.

Mount the Amp

At this point, you should mount the amp in that location you’ve selected.

Install the Wire

Look for the wire from the amplifier wire kit, ensure that it runs from the car battery through the car firewall then to the body and finally to the amplifier.

Also, try to find a grommet situated in the car firewall or you could use one that has wires running through it with enough space for the wire to go through.

Pay good attention while doing this.

If it’s hard to locate a grommet, you will have to make a space through the car firewall.

Ensure that the hole is not made into an electrical or the gas line, check the parts of the car firewall properly to confirm.

The grommet is used to protect the amp wire from wearing or getting shortened while passing the hole.

Mount the Car Fuse Holder at the Appropriate Location

The wire from the amplifier wire kit may likely have the normal fuse holder pre-installed. If this is the case, then you have to proceed with the next step.

If it is not pre-installed, then look for a good location that is close to the car battery and install your car fuse holder (which comes with the kit) 6’’ or less from the original battery.

Note that even if the fuse gets to blow, the small stretch of wire between the car battery and also the car fuse holder should have charge, and this could lead to a fire outbreak if there’s an accident.

Fix the car holder to the best location with the cable tie to prevent it from hanging loose or bouncing around.

Cut out a piece from the edge of the wire to remove the insulation from both ends using a cable stripper.

Compress the car terminal ring to an edge of the piece of cable and link the holder to the other edge.

Remove the insulation from the edge of the cable that leads right to the passenger seat and connect to the edge of the holder.

Installation of Multi-Amp

When you want to power multiple amps, you run one heavy-capacity power wire from the car battery to the dispersal block and link a lighter-capacity power cable or wire from the main block to the different amplifiers.

This step prevents potential noise issues after installation and makes your work come out fine.

Ensure that the power wire is strong enough to handle the whole current of the amplifiers at same time.

You should also check for the connection of a 2-amp system.

Connection of the Power Cable

Put the power wire on the battery positive terminal but this shouldn’t be close to the main battery post.

For other battery posts in the car, the best way to achieve this is simply to compress the ring terminal to the edge of the wire (Many power cables in kits that are always attached to the amp upon purchase).

How to install a car amplifier
Photo Credit: Peakpx.com

Be sure to detach the battery terminal’s bolt, slip the cable’s ring across the bolt to prevent any shocks or bridge and change the bolt.

A cable loom gives added protection good enough for the cable against the heat right inside the car engine compartment.

If your kit has a wire loom, thread it over the power cable until it reaches the firewall and cut to fit. Thread another piece over the short power wire running from holder to the battery.

Ground Wire

This should be installed as close to the amp’s location as you can and find a nut to your car’s metal panel to use.

If it’s hard to find a good ground bolt, make a small hole for the bolt. Be very careful so you make the hole into any wire, the car gas storage or even the brake line.

Compress the ring terminal of the amp (check for the one that comes with the amplifier) to a shorter piece of wire.

Scrape any painting, also clean the nut location very well, you can now screw the nut neatly to the car’s metal plate.

Use extra screws, star washer or even a lock washer or any other strategy or device that will keep electrical connection clean, tight, and safe.

You could also cover the connection with silicon caulk to avoid corrosion.

The remote cabled is located directly behind the car stereo. This usually comes in a white and blue wire.

The wire will notify your amp to switch on every time the car stereo is turned on (Usually happens when the car is switched on). You will have to detach the stereo the car radio to reach this cable.

Clear the insulation off a small section of this wire coming from the radio and the power lead that came with your wire kit and connect all together with solder.

The switch-on signals are usually +12 volts DC and If your radio doesn’t have the remote switch-on output like a radio, then you could reach for the switch-on signals from your car’s fuse box.

You can also connect your switch-on lead with any fused terminal made for output just as you use for radio.

Here’s an explanation, if it powers when the car is on. Using a fuse connector plus a 2A to 10A fuse will make this connection easier.

You will need to connect the power with your amp through the vehicle’s body- It’s often easy to connect the switch-on wire and RCA cables or you could also connect with the cable after it goes through the car firewall.

Additionally, the power cables should also connect on opposite parts of the car to reduce any unwanted noise and this does not affect the switch-on current.

Make the Signal Connection

If your dashboard receiver has preamplifier outputs, also connect your patch wires to them.

You should also route the wires to the direct opposite part of the car from the wire. It is very important to differentiate the patch wires from the cables to avoid noise problems.

At this point, you can reinstall the car amp in the dashboard.

Avoid the complete re-installation if it is possible. This will help you if you have to fix any problem.

If you use a radio without RCA output cables, you could get your amp’s input signal from the speaker wire connection.

The speaker will at this point be getting signals from the amplifier which will make the radio outputs available for the amplifier’s inputs.

You can do this through getting an output converter that will help adjust all the speaker signals for your amplifier’s input or getting an amp with speaker inputs.

You clip all wire behind the car radio and to your amplifier’s inputs.

Connecting Your Speaker

At this point, you need to make space for sound to move from your amplifier down to the speaker.

Your best bet is to connect a speaker cable from each amp output down to each of the speakers.

You need to gauge the wires first and this should be within the range of 14-16 for speakers and 12-14 for subwoofers.

You also need to know that the speech signal is not susceptible to picking any interference so it’s fine to connect your speaker cables near power wires.

You will have to connect the wires for the door speaker through the gasket or the boot, in order to secure the cables from getting squeezed at the door or damaged by the weather.

There may be a plug or another obstruction blocking the way, you can usually locate a place to make a hole through it big enough to fit your wire through.

Cut all the speaker cables and link the new cables directly to each of the amplifier’s speaker terminal.

However, it is expedient that you maintain the separation of the speaker wire connection in a straight form.

By implication, this involves that the positive terminal of the amplifier that will connect to the positive terminal of each of the speakers — and same thing is applicable in negative terminals.

In other words, this will ensure that your amp speakers will function in a mechanical phase — all the amp speaker cones moving towards the same direction with the same kind of signal — and often sounds balanced when the speakers are playing at same time.

The positive terminal and negative terminal of each of the speakers should be identified, and if this is not possible, the positive terminal is usually larger than the other negative terminal.

Using the Factory Speaker Wire Connection

Another way of sending signal from your amplifier to the speaker is to connect the wires from the receiver’s trappings that is directly behind it and where all the vehicle’s speaker connections can be accessed in one circuit.

You cut the wire for each speaker from the receiver’s trappings and connect to the speaker cable from the amplifier.

The signals can now flow directly from the amplifier to the speaker following the car’s original wire connection.

This technique usually works fine with systems that have 75 watts RMS of power in each channel.

Although more powerful amps would demand that you connect new speaker cables direct from the amplifier to each of the speakers.

Turning the Amplifier On

Check your car wiring properly from the car battery to the amplifier and speakers to confirm that all connections are secure and tight to prevent any stray wire strand that can cause an electrical bridge.

Especially, you have to ensure that the lower connection is safe.

Adjust all the amp’s gains to a minimum and turn off all the filters and any equalizer it may have.

Check that the fuse is installed in the holder properly. At this point, you can reconnect your vehicle’s negative battery wire.

At this point you can switch on the car ignition then switch on the stereo. Check that the amp powered up too (There should be a LED indicator somewhere).

Try to play a music track and increase the volume enough for you to hear.

At this point you have to verify that the sound is really coming from all the speakers or subwoofer located in the amp system.

If you get a clear sound from all the angles, you can conclude with the re-installation of the stereo with your car’s paneling.

Setting the Amplifier’s Gain

You should set your amp’s input or gain sensitivity to match the amplifier’s input level and the receiver’s output level.

This will result in maximum noise-free music with less background noise.

Troubleshooting Amp Installation

There are cases when you will encounter problems after installation may be due to several reasons which may likely affect the overall operations.

Below are the reasons your installation is still a hard cry even after reading the Crutchfield guide.

Amp doesn’t Power

To safely and properly troubleshoot a faulty electrical system you will have to use the multi-meter to measure system voltages and to check for continuity.

Measure the system voltage of the amp between the lower wire and the positive power terminal.

If you do not have any voltage, go to the second installation step, if +12 volts DC is available, move down to the third installation step.

Detach the in-line fuse close to the battery to check properly for continuity. If there is no continuity, this means the power fuse is bad and needs to be replaced. Good continuity will mean that the power wire is not connected anywhere on the line.

Video: Troubleshooting Car Amp Installation

Measure the system voltage of the amp between the lower wire and the remote switch-on terminals.

If the voltage is +12 volts DC, then it means that either the amplifier’s onboard fuses are bad or blown or there’s something wrong in the amp and you have to take it back to the dealer for fixing.

If you don’t find any voltage, the implication is that it is either not connected accurately or broken.

Amp Powers on But the Speakers don’t Produce Any Sound

You should try increasing the amp’s gain a bit. Ensure that all filters are turned off or not activated.

Check the source. Ensure that the source is playing a track and not idle. For instance, when some speakers are not playing and others are playing, it is likely to be as a result of the balance control not being adjusted to the center.

Also, there are receivers that have a muting function, so it is likely the button has been pressed.  

Most amplifiers like the Pioneer GM-A6704 Car amp don’t have this issue

Also, Check That the RCA Wires are Plugged

Switch off the amp receiver and amplifier. Remove all the wires from the amp receiver. Switch the receiver with the amplifier back on.

At this point touch the pin inside the plugs with one finger. If your wire connection is okay, you will likely hear a sound coming from the speaker.

Test the wires this way and if you hear a sound from the speakers then this means the receiver is not sending signal and will have to be checked by a technician.

In the case of using line converter If you hear no humming on any channel, turn off the receiver with the amp and plug the RCAs back in.

Having read through this article, the installation of your car amplifier shouldn’t be a hard task. Just follow the steps thoroughly for guidance. You can also check out the Pioneer GM-A6704 Car amp if you need help in choosing a good amp.

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