2002-2009 Chevrolet TrailBlazer
How to install your new stereo and speakers
2002 • 2003 • 2004 • 2005 • 2006 • 2007 • 2008 • 2009
In a nutshell: This article is an overview of your TrailBlazer's audio system and its upgrade options. Use our vehicle selector to find the gear that will fit your SUV.
Overview of the Chevy TrailBlazer
When the TrailBlazer debuted in 2002, Chevy was still using their long-running "Like a Rock" ad campaign. And with big, comfy vehicles like this one, the theme was appropriate. The TrailBlazer, like most GM trucks and SUVs of the era, offered a solid engine, a solid chassis, solid looks, and solid value. Used TrailBlazers still do, if you happen to find a nice one.
The TrailBlazer was available in "Regular" or the stretched EXT model, which seated seven people in reasonable comfort. Performance-oriented customers could choose the Corvette-motored SS model starting in 2006. As the first SUV to carry Chevy's legendary Super Sport designation, it accelerated, turned, and stopped way better than a large, truck-based SUV had any right to.
That's the one we'd want, but if you need a solid mid-sized SUV for everyday duties, any TrailBlazer is a pretty sharp choice. A new stereo will add great sound and up-to-date functionality to your fun family hauler.
The optional nav receiver can be replaced by a variety of newer models (Crutchfield Research Photo)
The TrailBlazer's factory stereo system
The factory stereo systems are, like most factory stereo systems, pretty dull. The Bose® system was a distinct improvement over the base model, but it's still getting on in years and you can do better. A healthy number of single-DIN (2" tall) and double-DIN (4" tall) stereos will fit right in, with the help of a dash kit that's designed specifically for your TrailBlazer.
Depending on the receiver you choose, you may have to unbolt or cut out the factory radio's rear support bracket to create the space necessary for the new receiver. That info will be presented to you before you buy anything, so don't stress. If you do need to deal with the bracket, that's not worth stressing about, either. It's not a structurally important piece and it's not that hard to remove.
You'll need to remove this bracket to install a new receiver. It's not as hard as you might think. (Crutchfield Research Photo)
The TrailBlazer's audible safety alerts (aka "warning chimes") are delivered through the factory radio. You'll need an adapter that retains the factory warning chime (plus OnStar) and provides a switched 12-volt power source for your new radio. Crutchfield strongly recommends that you use the recommended adapter when you replace your radio. The adapter isn't free, but when you purchase it along with your new receiver, we'll give you a very nice discount off the retail price.
You'll also need an antenna adapter and a wiring harness adapter that will allow you to connect the new radio without having to cut into the factory wiring. All of those items are available at a healthy discount, too, and you'll also get a free Crutchfield MasterSheet, which contains illustrated, step-by-step instructions on how to install a new stereo and speakers in your truck.
The base radio had a cassette deck, which you really don't need anymore, right? (Crutchfield Research Photo)
Replacing the factory radio in your TrailBlazer
Before you do anything else, set the truck's parking brake and disconnect the negative battery cable to prevent any electrical shorts. Once everything's secure, you'll start by removing two 7mm screws from the driver’s knee panel. There may or may not be screw covers over them, but if there are, you can remove them by gently popping them off with a screwdriver. Either way, once the screws are removed, you can pry out the top edge of the knee panel and release the retaining clips. It's okay to just let the panel hang while you're doing everything else you need to do.
The rest of the process is pretty straightforward. Remove three Phillips screws from the bottom of the dash trim panel that's exposed by lowering the knee panel. Next, remove one Phillips screw, located to the left side of the 12 volt power outlet, from the dash trim panel. Then you'll remove two more Phillips screws from just above the instrument cluster.
Detailed stereo and speaker removal instructions
Place the steering wheel in its lowest position, then carefully pry around all edges of the dash trim panel to release six retaining clips. Disconnect the wiring harnesses and work the dash trim panel over the steering column until the panel's out of the way.
With that, all you need to do is remove the three 7mm screws securing the factory radio, disconnect everything, and set it aside. Secure the new receiver to the mounting bracket following the instructions included with the bracket, make your wiring connections, then install the stereo. Test it out to make sure it's working and, if it is, start putting the dash back together.
Tools needed: Phillips screwdriver, panel tool, 7mm socket, ratchet & extension
Steering wheel audio controls
It's relatively easy to retain the steering wheel audio controls when you install a new stereo in your TrailBlazer. When you enter your vehicle information, our database will choose the adapter you need to make your factory steering wheel controls work with your new receiver.
The front door speakers vary, depending on whether you have the base or the Bose system. This is a Bose speaker. (Crutchfield Research Photo)
Replacing the factory speakers in your TrailBlazer
All TrailBlazers, including the EXT, have factory speakers in the dash, front doors, and rear doors.
The corner dash tweeters aren't hard to replace, but you'll need to pay attention to what you're doing (Crutchfield Research Photo)
Replacing your TrailBlazer's dash corner speakers
Bose-equipped trucks feature tweeters underneath grilles on the far left and right sides of the dash. If you want to replace these tweeters, you'll need to remove the A-pillars and the top dash panel.
This isn't hard to do, but the airbag assembly is located behind the dash trim panel, so be very careful when you're doing this. Another reason to be careful (but a less-urgent one) is that you don't want to damage the panels.
There are no mounting brackets or wiring harnesses available for these speakers, so you'll need to use our universal backstraps (or silicone or hot glue) to hold them in place and Posi-Products connectors to connect your new tweeters to the factory wiring.
Your new speakers might not include mounting screws, so check the box before you start. If you have to make a run to the hardware store, it's obviously best to do it before you take your dashboard apart.
Tools needed: Phillips screwdriver, flat blade screwdriver, panel tool, 7mm socket, ratchet & extension
You have plenty of options when you're replacing the TrailBlazer's front door speakers (Crutchfield Research Photo)
Replacing your TrailBlazer's front door speakers
The TrailBlazer's standard front speakers are 4-ohm 6-3/4" units, while the Bose-equipped models contain 8" 2-ohm speakers. Both varieties can be replaced with a wide variety of aftermarket speakers, though you will need mounting brackets to install smaller speakers in bigger cavities. They're included at a deep discount with your Crutchfield speaker purchase.
You'll need to remove the door panel to access these speakers, but that's a straightforward process, and it's all explained in your Crutchfield MasterSheet.
The standard 6-3/4" woofer is a component piece with a tweeter just above it. The woofer receives a full-range signal, so you can ignore the tweeter and swap in a new full-range speaker. You could also install new component speakers here pretty easily.
You can use the factory brackets and grilles with your new speakers, but you may need to grind off some material to get a perfect fit. You'll also have to remove the locating tabs from the factory speaker bracket before mounting a new speaker or bracket. Just use a pair of pliers to snap them off. Don't worry about the bracket — this minor tweak won't affect the structural integrity.
In the Bose system, the factory front door speaker is a woofer that receives a low-pass signal from the factory amp. When you install an aftermarket speaker, you'll only get bass unless you bypass the factory amp, which is located in the right rear cargo area.
Once you're done installing your speakers, test them out to make sure they're working properly. And before you reinstall the door panel, make sure the speaker wires aren't interfering with the windows and test the door lock and release operation.
Tools needed: Panel tool, 10mm and 1/4" sockets, ratchet & extension, Torx T-15 driver, pliers
Replacing the rear door speakers is pretty much the same as replacing the front door speakers (Crutchfield Research Photo)
Replacing your TrailBlazer's rear door speakers
Replacing the rear speakers in your TrailBlazer is basically a lot like replacing the ones up front. You'll need to remove the door panels, of course, being careful not to damage the sometimes-snug plastic retaining clips.
As with the front speakers, you'll use a pair of pliers to break off the line-up tabs on the factory speaker bracket. This will allow your new speaker to fit flush against the bracket. You may also need to break off the three square mounting tabs on the speaker/bracket assembly.
Depending on your TrailBlazer's year and factory equipment, everything from 5-1/4" to 6-3/4" aftermarket speakers will fit in the rear doors. Once you've entered your vehicle information into our Outfit My Car tool, you'll see a complete array of what's available for your truck.
Tools needed: Phillips screwdriver, small flat blade screwdriver, panel tool, 1/4" and 7mm sockets, ratchet & extension, Torx T15 driver, pliers
The JL Audio Stealthbox blends right into the rear cargo area
Bass in your TrailBlazer
Like most SUVs, "mid-size" or otherwise, the TrailBlazer has room for just about anything you want to toss into the cargo area, and that endless list definitely includes subwoofers. If you want to install a subwoofer box filled with gi-normous subs (and the amps to power them), you have a 45" W x 14" H x 34" D space to work with.
If you still use your SUV as a people-and-gear carrier, then you'll need all that cargo space. You can choose from a wide variety of powered subwoofers, all of which will deliver an impressive amount of thump without taking up all the space you were saving for groceries and sports equipment.
There's also the custom-fit option, which will give you outstanding performance while blending seamlessly into your TrailBlazer's interior décor. JL Audio offers a custom Stealthbox enclosure that holds a 10" subwoofer. You can install it behind the right rear panel in the cargo area. The look is incredibly subtle, but the bass sound is noticeably better than stock. It's not compatible with the optional GM cargo organizer, though, so keep that in mind.
There's also a Q-Forms custom enclosure which mounts in the same location and can also house a 10" subwoofer. It's available in Black Carbon Fiber or Burlwood.
Other options for your TrailBlazer
There are plenty of other ways to improve your TrailBlazer. Here are some of the ways Crutchfield can help.
Improve audio performance with kick panel speakers
Q-Forms Kick Panel Pods can be installed in place of the stock front kick panels. This is not an easy installation for the average DIY-er, but the improvement to your vehicle's sound staging is dramatic because the pods point the 6-1/2" speakers of your choice (the pods are unloaded) in the direction of your ears. They're available in colors that match your TrailBlazer's interior, too, so they'll look great.
See more with a rear-view camera
With a vehicle this large, you really need to be aware of your surroundings. A rear-view camera is a big help when you're backing up in a crowded parking lot. Connect it to your nav or DVD receiver for increased awareness and safety.
Seal in sound with speaker baffles
We frequently suggest foam speaker baffles for other vehicles, but for an SUV like this, we strongly recommend them. Those big doors can waste a lot of great sound, and these rubber baffles are an inexpensive way to rein it back in. They're easy to install, and they'll give you improved performance while also protecting your speakers.
Protect your truck with a security system
Installing a security system in your TrailBlazer isn't easy (security systems usually aren't), but it's definitely a good idea. Our Crutchfield Advisors can help figure out what you need to get the job done, but we usually recommend taking your car and new gear to a professional installer.
Find the audio gear that fits your car or truck
Visit our Outfit My Car page and enter your vehicle information to see stereos, speakers, subs, and other audio accessories that will work in your vehicle.