How To Fix Speaker Wire In Your Car Like A Pro

Got speaker sound or wiring problems? What can you do?

In this article, you’ll learn how to troubleshoot or fix speaker wire in your car. I’ll cover a number of important things you may be wondering:

  • How to troubleshoot no sound (is it the speaker wire or other problems?)
  • Can you repair speaker wire?
  • How to fix speaker wire like a pro (and how not to).
  • A cool little car audio installer trick for checking wire & speakers quickly.

Plus lots more to learn. Read on to learn more!

Troubleshooting bad speaker wire or no sound from speakers

troubleshooting no sound from speakers bad speaker wire section image

One very important thing is to be sure exactly why you’re not getting sound from one or more speakers. For example, is it really bad speaker wiring? What if it’s actually something else entirely?

In this section we’ll cover what you need to know before you start working or before spending a dime.

Why is my speaker not working in my car?

Speakers may fail to work for one or more reasons:

  1. Bad speaker: it’s blown (bad voice coil), a failed wire, or a bad connection at the speaker.
  2. Bad wiring: One or more wires to your speaker(s) had a missing or very poor connection.
  3. Bad audio source (no sound from the car stereo or amplifier): this can be due to a number of things both normal or very severe (see below).

Troubleshooting no sound from a car speaker

how to troubleshoot no car speaker sound diagram

If you want to troubleshoot one or more speakers that have no sound you’ll want to avoid the “guessing game.” Your time is much better spent using some simple but professional steps that’ll get you a sure answer.

It’s only a little bit of work, after all, and can save you a lot of money and hassle (as opposed to buying things only to find out they don’t solve the problem!)

To find out if you’ve got bad speaker wire (less likely, in most cases) or a bad speaker or stereo/amp problem (more likely, more often than not) do the following:

  1. Remove a/the speaker with no sound. Find a known good working speaker (this is important!) and connect it to the wiring of the speaker you removed. Play some music and if the problem is solved you’re dealing with a bad speaker. Otherwise, there’s more investigating to do.
  2. If #1 didn’t work, you’ll want to remove the car stereo (when possible) and connect the test speaker to one of the speaker output channels, removing any speaker connected to the wiring currently. If you’re driving your speakers with an amplifier, disconnect one and connect the test speaker in its place. If you don’t have sound with the head unit, it’s possibly burned out or there’s another internal problem. If using an amplifier, it could be (a) burned-out outputs, (b) no signal from the car stereo, or (c) an installation-related problem not supplying power properly.
  3. If you do have sound in step #2, then you may indeed have a problem with the speaker wiring. To verify, connect the speaker wire ends with a speaker removed, making sure they have a direct, clean connection. You can use a short jumper wire when factory connectors are in use. One the radio or amp end, with the speaker wire disconnected, test resistance or continuity using a test meter. Good speaker wire will cause the meter to beep or measure around zero Ohms. High resistance or no change in the reading means there’s a problem with the speaker wire.

Once you’ve narrowed it down, and if the speaker wire turns out to be the problem, you may find it easier to run new speaker wire aside from having to run it through the body of the vehicle. For example, many vehicles make it very hard to run wire through the body to the doors.

Note: If you don’t have a standard 4 ohm car speaker available to test with, that’s ok. You can also use an 8 ohm or 6 ohm home stereo speaker if you like. Both are safe to use for test purposes.

In that case, it’s sometimes easier just to keep the factory door wiring and connect new wire under the dashboard when possible. For dash speakers, it’s often fairly straightforward to run new speaker wire from the radio or amp.

PRO TIP: One installer’s trick is to use a low-voltage battery like a AA, C, D, or even a 9V to touch across speaker wires to check for sound from a speaker. This verifies the speaker is at least able to produce sound and also that the wiring works.

By touching the battery to the speaker wiring momentarily you’ll hear sound from the speaker if the wire is ok & and the speaker itself can function.

Only use a small, low current battery – never use a big 12V battery for example! Small batteries can’t damage a speaker but high-current ones can.

Can you repair speaker wire?

can you repair speaker wire man thinking section image

The good news is that yes, in most cases speaker wire can be repaired or lengthened.

There are some important things to know, however:

  • Very thin or very poor quality speaker wire may not be worth fixing or is very difficult to work with. In that case, it’s sometimes better to replace it with something of decent quality. This is especially true for junk wire sold misrepresenting its actual gauge – you end up with big insulation but only a handful of thin, weak wire strands that break easily and are a huge pain in the behind to try and work with!
  • Non-standard wire used as speaker wire like telephone cable, audio signal wiring, or household/pure aluminum wire is often too hard to work with. In that situation, it may be possible to use crimp connectors but I don’t recommend most people trying it. (It’s often better – and a lot easier – to replace it with proper wiring)
  • You do not have to use the same gauge of speaker wireFor example, if you’re wishing to repair 16 gauge speaker wire you can use a different size that’s handy if needed.

Standard stranded copper or copper-clad aluminum (CCA) speaker wire can be repaired using some methods I’ll share below. Bear in mind, however, that the repair is only as good as your work.

Why not just replace the speaker wire instead of repairing it?

Replacing an entire length of speaker wire simply isn’t necessary most of the time. In cases where the wire can be fixed, it wastes time, money, and effort. I’ve never understood why some people insist on doing it when it’s not needed (aside from upgrading or for other reasons).

Speaker wire is very similar to stranded hook-up wire (power wire) meaning even if cut and re-connected (repaired), if the connection is solid it’s as good as new. As long as the electrical connection is of high quality and doesn’t oxidize over time the wire will still have full power-carrying capacity without a loss.

Speaker wire (especially pure copper wire these days!) can get expensive to replace. In some cases, like the speaker wire running to factory locations in cars or trucks, it would be a huge amount of effort with no benefit. Extending wire is less time, work, and money – and especially good if you’ve got spare wire lying around.

If you’re repairing speaker wire that’s already of a good enough quality & wire gauge, you’re fine. 

How to fix car speaker wire like a professional

how to repair car speaker wire diagram

There are all sorts of connectors or terminals you can use to fix wire. However, I don’t want you to have problems later. If you want truly professional results that are reliable and won’t give you problems later, there are two great ways to do this:

  1. Soldering wire together.
  2. Using crimp connectors and a crimp tool.

Soldering wire properly results in an excellent connection that’s just as good as the original uncut wire. The downside is that it takes more time and effort.

Crimp connectors (also called “butt connectors”) are what I normally use. Crimp connectors are a great compromise between results, time, and effort and give nice results in only a few minutes.

They’re commonly used by professionals like myself for car and truck audio installations. Crimp connectors are what I’d recommend for most people if you’re not experienced soldering wire.

The downside to crimp connectors is that it’ll cost you a few dollars for the connectors and you’ll need a crimp tool as well.

1. Soldering speaker wire

Image showing steps for how to solder speaker wire

To properly solder speaker wires together:

  1. Cut & strip the speaker wire (at least 1/2″ length of bare wire on each end is needed).
  2. Hold up both ends to form an “X” shape with the wire facing opposite directions.
  3. Hold both ends and tightly twist each end around the other until they’re completely wrapped over each other facing the opposite direction.
  4. Let your soldering iron heat up. Once it’s fully heated, apply heat to the wire with the tip. After a few seconds apply the solder until it begins to flow. Keep adding solder until the wire is fully saturated with it. 
  5. Rotate the wire to the other side and apply the solder until all of the wire is fully saturated with the solder.
  6. Allow the wire to cool for a few moments.
  7. Tear 2 short pieces of electrical tape. Starting at the insulation and at an angle, tightly wrap the tape until it is fully covered.

It’s important to fully cover the wire once you’re done. That’s to prevent the wire from touching each other and cause a short circuit that can permanently damage the output components in an amplifier or stereo.

Note: If you’d rather you can also use heat shrink tubing for excellent insulation that’s even better than electrical tape and looks nice, too.

2. Using crimp connectors

How to use crimp connectors with wire instruction steps image

Using crimp connectors with speaker wire isn’t very hard – I promise! You’ll get the hang of it after a few tries.

How to crimp speaker wire properly:

  1. Strip the wire leaving 3/8″ to 1/2″ bare wire exposed for each wire end.
  2. Tightly twist the wire so it can be pushed into the connector properly.
  3. Insert the wire into one end firmly, pushing it into the metal contact inside. Be sure to insert it fully.
  4. Place the connector into the crimp tool in the appropriate position in the tool, near the end of the connector.
  5. Crimp very hard with the tool to make press the connector down hard, holding the wire inside permanently.
  6. Repeat the same for the other side of the connector and the other wire.
Tip: For best results, once you’re done pull gently on the wire while holding the connector. The wire shouldn’t come out. If it does, you’ve crimped it poorly and will need to do it over again.

What to avoid doing

diagram showing how not to repair speaker wire

Unfortunately I’ve seen this a lot: 

  • The “twist and tape” way of connecting speaker wire.
  • Working with oxidized wire instead of clean wire strands.

Simply twisting and taping wire together is a recipe for disaster! Wire can come apart since there’s no permanent connection, causing sound problems and even short-circuits that could ruin your car stereo or amp.

When exposed to heat over time, electrical tape adhesive tends to lose its stickiness and the tape can slide off, exposing the bare wire.

Oxidized wire is copper or other wire conductors that have been exposed to air and build up a coating that adds resistance in between connections. It can also cause issues with power loss, bad sound, and more. Always be sure you’re working with “fresh” (clean, shiny) wire ends. You may need to cut and strip fresh wire ends in some cases.

What kind of solder do I use for speaker wire?

example image of solder for speaker wire

Pictured here are great options for soldering speaker wires, both on a standard spool or in a tube version. Regular .032″ 60/40 rosin core solder is excellent for wire and gives great results when used correctly.

For soldering speaker wire I recommend standard 60/40, .032″ rosin core electronics solder. Using smaller gauge solder with wire is not recommended as in my experience it’s much slower trying to add more and more and more as the solder flows. It really does make the work more difficult.

Rosin core solder is great for making sure the exposed wire strands are cleaned and let the solder flow and coat the conductors well as it’s heated. Additionally, bear in mind that lead-free solder is more difficult to use and often results in a bad solder job.

For that reason, I recommend that you keep using regular 60/40 lead/tin solder. It’s also great for other little projects you may need to work on later (very nice for a lot of electronics or wiring projects that require a good quality solder).

Do I need to buy expensive speaker wire for my car?

do I need to buy expensive speaker wire section image

No, you do not need expensive or fancy speaker wire. A good enough quality wire of the correct gauge and type is fine.

When it comes to speaker wire, spending more money for a more expensive product doesn’t give you any better sound than standard “good enough” quality wire does. That’s because electrical wire that is of the proper conductor size (gauge) and conductivity is absolutely fine.

What to look for in speaker wire

When shopping for speaker wire, there’s really not too much to worry about:

  1. Decent quality wire of the correct American Wire Gauge (AWG) rating.
  2. Wire that’s of fairly good quality and strand count.

I strongly recommend you avoid the absolute cheapest wire you can find. Chinese manufacturers use misleading wire descriptions and oversized wire insulation to give the impression you’re getting your money’s worth but instead the wire will be undersized in wire gauge and of poor quality.

Similarly, amp wiring kits have been known to have the same problem for power and ground wires.

You’ll want to get wire that’s rated made with the correct AWG gauge as claimed to be sure you get what you pay for. You don’t need to spend a fortune, but be sure to deal with reputable retailers in-store or online to be sure.

What to know about copper-clad aluminum wire

Copper clad aluminum vs copper speaker wire illustrated diagram

Because of the rising cost of copper metal these days, what you’ll discover (whether by accident or when carefully browsing during shopping) is that it’s harder and harder to find pure copper wire for sale. What’s being sold these days in many cases is not pure but instead copper-clad aluminum wire (CCA). 

There are two problems with it:

  • CCA speaker wire is stiffer and a bit harder to work with since it’s less flexible than pure copper wire.
  • Aluminum has about 61% of the conductivity of copper. In other words, it has 39% more resistance to the flow of electrical current.

What’s sad is that unsuspecting buyers spend money thinking they’re getting the same quality as real copper speaker wire. However, never assume today’s wire is real copper – it’s most likely CCA unless it says 100% copper in the specifications.

If it doesn’t say so on the package, it’s likely CCA wire so be aware!

Should you avoid CCA wire?

No, it’s actually fine to use. However, what you should know is that when buying CCA speaker wire, you’ll need to go up one wire gauge (minimum) to have the same wire performance as the regular copper wire size.

For example, if you’re normally looking for 18AWG copper wire, the most popular for car and truck speaker installations, you’ll need to get 16AWG in the CCA version to get the same power handling.

Personally, I still prefer using pure copper wire for installations because it’s so flexible and easier to work with. However, it can take a bit more time to find it when shopping so it’s a matter of preference once you understand the differences.


About the author

Marty is an experienced electrical, electronics, and embedded firmware design engineer passionate about audio and DIY. He worked professionally as an MECP-certified mobile installer for years before moving into the engineering field. Read more »

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