2003-07 Chevrolet Silverado 1500 Extended Cab

2003 Chevrolet Silverado 1500 Extended Cab (Crutchfield Research Photo)

Chevy’s Silverado is a workhorse, one of the most popular vehicles on the road today. GM built this particular version from 2003 to 2006, and then kept it on as the 2007 Silverado Classic when they switched to the new body style. It’s a great-looking truck, but the factory stereo comes up a little short. There are plenty of ways to bring it up-to-date with better sound and extra features that’ll make this Silverado a complete package.

Replacing your factory radio

This Silverado’s factory radio also houses the truck’s warning chimes. (Crutchfield Research Photo)

These Silverados were equipped with a 4" tall AM/FM CD player, with options for XM Satellite Radio, OnStar®, and a Bose® speaker system. You can install almost any 2" tall (single-DIN) or 4" tall (double-DIN) stereo in the Silverado dash opening, but you’ll need to use a hacksaw to remove the metal support bar behind the factory radio to install any car stereo that’s over 6-3/8" deep. Also, adding a stereo with a flip-out screen isn’t a good idea in this truck, because the dash overhang doesn’t allow the screen to fully extend when open.

You'll need a mounting kit to trim out the new radio, a wiring harness that allows you to connect your new radio without having to cut the factory wiring, and an antenna adapter that allows you to connect the Chevy antenna plug to your new radio. (Crutchfield includes these installation parts free with most orders, along with our step-by-step instructions for your Silverado).

You’ll have to remove a large dash piece to access and remove the factory radio. (Crutchfield Research Photo)

Keeping important factory features
It’s important to get the necessary adapter to retain the factory warning chime features and, if you have OnStar, you’ll need an adapter that allows you to retain all those safety and convenience features. If you have the GM satellite radio option, you’ll lose it when you replace the factory radio. You can always pick a stereo that offers satellite radio reception, either from a built-in tuner or an add-on tuner, then call SiriusXM to transfer your subscription.

Metra’s GMOS-04 interface looks pretty scary, but it does a great job of integrating a new stereo into your Bose-equipped Silverado.

Bose® system
The logo on the front door speaker grilles tells you that you have the Bose system. Metra’s GMOS-04 interface connects your new stereo to the Bose amplifier and speakers, while retaining all warning chimes and OnStar functionality (if activated). Note: your new stereo must have front and rear preamp outputs to work properly with the Metra interface.

Steering wheel audio controls
There are two companies (PAC and Axxess) that make adapters for connecting your steering wheel audio controls to a new car stereo. We recommend the Axxess ASWC-1 adapter for this truck, along with Metra's 708114 harness — this combination allows you to connect your steering wheel audio controls to your new stereo without any splicing. Nice.

Tools needed for an aftermarket radio installation:

• Panel tool,
• 7mm SRE,
• hack saw blade (to remove rear support)

Replacing your factory speakers

Silverado front door with Bose speaker (Crutchfield Research Photo)

Front door speakers
Stock speakers for the front of the Silverado are 6-1/2", a common size with great aftermarket support, and they utilize a simple clip-in plate for easy removal and installation. You won’t have trouble finding a speaker to fit any musical taste or budget. You can put a 5-1/4" or 6-1/2" speaker in the front door with the help of an inexpensive mounting bracket, and you can even fit the slightly larger 6-3/4" speaker in there if you’re willing to drill some new screw holes. Crutchfield includes the mounting bracket (if needed) and speaker wiring harnesses with every speaker order. Trucks with the Bose system will have a tweeter up in the pillars; non-Bose vehicles may have a tweeter next to the speaker in the door.

Bose® system
If you have the Bose system, your Silverado will have tweeters in the A-pillars (you’ll see the small grilles just above the dash by the windshield).

The Bose tweeter in the front pillar (Crutchfield Research Photo)

These are also easy to remove, and offer a handy mounting spot for an aftermarket tweeter. You’ll have to fashion a mounting plate to install a tweeter in the pillar, but some tweeters include adjustable brackets for locations like this.

Rear door speakers
You’ll find 4"x6" speakers in the rear doors in this extended cab Silverado, or if you have the Bose system, a round speaker in a 4"x6" bracket. Once you’ve removed the door panels to get these speakers, they’re extremely easy to take out, thanks to their clip-in plates.

The rear door speaker in the Bose system is a round speaker in a 4"x6" bracket. (Crutchfield Research Photo)

You can install 4"x6" and 4"x6" plate speakers in these openings, or go with a 4" or 3-1/2" if you prefer. You’ll have to drill new screw holes no matter what you put in there, and we recommend using speaker baffles to act as gaskets because the new speakers will have some air gaps around the frames once installed.

Tools needed for speaker removal:

• Phillips and flat blade screwdrivers,
• panel tool,
• 7mm SRE,
• drill with 1/8" bit,
• plus Torx T20 driver for 2005-up models

Bass in your Silverado

Some later models with the Bose system have a powered subwoofer mounted in the center console. You can remove this sub and its small amplifier, and it's possible to install an aftermarket sub in this location if you power it with a new amp. We don’t recommend this route because it requires a lot of time and sweat.

The Bose sub is mounted in the center console for bass reinforcement. (Crutchfield Research Photo)

A closer look at the factory sub — it's a slightly oblong 6-3/4" subwoofer (Crutchfield Research Photo)

Here’s a better way to get great bass in this Silverado. You’ll find a large assortment of aftermarket enclosures that fit into a variety of locations in this truck, many already loaded with a sub, and some even with a built-in amp. The sub will still be tucked out of the way but will produce a much deeper, tighter bass kick based on the power of the amp you add.

This MTX ThunderForm, loaded with a 10" sub and 200-watt amp, mounts under the rear seat. (Courtesy of MTX)

More options

Amps
Being a pickup truck, the Silverado has a noisy cabin. If you really want to hear your music without taxing your speakers, add an amp. There are plenty of inexpensive options that will give you the ability to hear your music loud and clear, especially when paired with some upgraded speakers. Mounting options abound; a best bet is under the front or rear seats.

Satellite radio
If your Silverado came from Chevy with satellite radio, you’ll lose it when you remove the factory stereo. You'll have a choice of choosing a new radio that works with an outboard SiriusXM tuner, or buying a Dock & Play radio which you can move from your vehicle into your home.

Security and remote start options
There's nothing out of the ordinary when it comes to installing security equipment in this vehicle. The XK01 or XK09 XpressKit interfaces would be the best choice — they're ready to work in this vehicle right out of the box, no extra programming required. Both interfaces come with great instructions. You will need an extra relay to add a second accessory wire for remote start.

Navigation
An in-dash navigation receiver is an excellent option in this truck, if you’re willing to cut out the support that held up the factory radio. Or you can use a portable navigation unit, which you can move between vehicles as needed and keep tucked in a storage compartment when not in use.

3 ways to upgrade your Silverado

Quick & easy
This truck is easy to upgrade, so go ahead and swap out the front speakers and replace the factory stereo with a stereo that puts out more power. The difference in sound quality will be impressive, even if you keep the Bose amplifier. Your options for an aftermarket stereo are almost unlimited once you knock out that rear support, so spend a little more on a deck that you can upgrade in the future (preamp outputs, Bluetooth® functionality, iPod® adapters, etc.). You’ll need to pick up a couple of adapters to retain features like OnStar, steering wheel controls and door chimes, so factor that into your budget.

More bump in your truck
Once you have a new head unit with preamp outputs, expand your system with some amps and a subwoofer. The custom made enclosures for this truck are amazing — they tuck out of the way, and some come preloaded with some of the best subs on the market. Make sure you feed them enough power to really let them achieve their full potential.

Safety, sound and performance
Head unit, speakers, amps and subs — your truck sounds great, now make it more functional. Add a Bluetooth interface to keep you safe on the road by allowing you to take calls through your car stereo hands-free. Or mount a rear-view camera on the back of your Silverado, then connect it to your in-dash DVD receiver so you can get a clear view when you're backing up.