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How to get through your car's firewall

Deciphering the tricky part of amplifier installation

When installing a new amplifier in your car, one of the most difficult steps is figuring out how to get the power wire from the engine compartment into the interior of the vehicle. You need to find a way to get that big wire through the firewall.

The secret is to use an existing pass-through, which will have a thick rubber plug or "grommet" sealing the passage. Sometimes you'll have to use a grommet that already has wires running through it and sometimes you'll be lucky enough to find an unused grommet. It all depends on the vehicle. Either way, the process is the same.

Amplifier installation help

In this video, we'll show you how to manage this task, and share some expert tips and tricks to make it easier. And if you purchased your amp from Crutchfield, you'll have the benefit of our outstanding tech support team standing by if you have any questions. If you're having trouble finding the best place to get through the firewall, just give them a call. 

If you're still trying to figure out what you need to purchase for your amplifier installation, talk to our advisors. They answer questions about this stuff every day, and they'll be happy to help you, too. 

Video Transcript

We're going to run this power wire up through here. We're going to put it in some flex loom to keep it protected from the heat of the engine. We're going to install a fuse somewhere in this neighborhood right here that will keep our entire vehicle safe in case there's any kind of short in the power wire, all the way from the front of the car to the back of the car.

We're going to run it over there, to a nice big huge grommet in the firewall where a lot of the factory wires go from the engine compartment through the firewall and into the passenger compartment. We're going to use this knife to poke a small hole in the rubber next to the wires, making sure not to cut any of the wires of course, and then we're going to poke this coat hanger through so that we can fish our wire through the grommet.

So let's see here, all right, that should do. I'm going to take this coat hanger, and I've already put a little hook on it. The idea here is that once we get the coat hanger through and we find it on the other side behind the glove compartment, we're going to take this power ring, just hook it on and pull it right back through. That's the idea, hopefully it works out just that easily.

All right, got the coat hanger through the hole and I'm pushing it through pretty much almost all the way, so just there's still enough for me to grab on this side and pull it back once I've got it connected to the power ring on the other side. So now we're going to go around to behind the glove compartment see if we can find our coat hanger and that hook to hook the wire on to. All right, let's pull our wire through. Oh yeah, just like it's supposed to work.

And if you need any help picking out an amp and a sub, or any combination thereof, check out Crutchfield. Give us a call we can certainly help you get the right stuff. And of course, we can help you get it installed as well.

  • Gary Schmidt from Plano

    Posted on 1/15/2018

    Works great on most cars . But on Saabs not so well double firewall

  • Mark Baxter from Summerton

    Posted on 5/18/2017

    Long time customer. I can honestly Crutchfield has the best support & advice team.

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