Whether you are upgrading your factory stereo or upgrading to a navigation system, it can be handy to know how to install a GMC Sierra radio. Today we’ll be showing you how to install a GMC Sierra radio in a 2008 GMC Sierra 1500. And if you want navigation in your truck, but it didn’t come with it from the factory, a factory navigation head unit can be a great choice.
Considering this generation of GMC Sierra is very similar to the GMC Acadia or Saturn Outlook, this makes for a great upgrade. Not to mention how relatively easy and straightforward that kind of install would be. Combined with our how to install a GMC Sierra radio, you can wire in any additional device, such as a GPS, DVD player or more.
Today I’ll be showing you how to remove as well as how to install a GMC Sierra radio or aftermarket head unit. All wires and wire colors should match before you attempt to wire anything into your vehicle. As always, use our DIY Guides on how to install a radio at your own risk and make sure to work safely with your wiring.
Begin by making sure your GMC Sierra is in the PARK position and that your parking brake has been engaged. Now reach up and grab the top bonnet of your dashboard above your radio.
This outer layer can simply pull off with the right amount of tug, make sure to evenly place your hands around the top of the unit. Pull evenly and downward to disengage the GMC Sierra radio trim. Once you have this bezel removed, you can access the bolts as well as any electrical connectors you may need to disconnect.
Once you have this bezel taken off, you’ve got free access to the GMC factory radio and the bolts you need to remove.
Now you can undo the bolts holding the radio and climate controls to the dash. Unplug your traction control button and remove the bezel around the radio.
Remove the bolts that run alongside either side of your factory radio assembly, and then you can gently remove your GMC Sierra radio. You now know How To Install a GMC Sierra radio, and if you need the 2008 GMC Sierra radio wiring diagram, we’ve included it below.
2008 GMC Sierra radio Wiring Guide
Car Radio Battery Constant 12v+ Wire: Red/White
Car Radio Accessory Switched 12v+ Wire: Dark Green
Car Radio Ground Wire: Black
Car Stereo Dimmer Wire: Yellow
Car Stereo Amplifier Location: Under the Rear Center Console
Car Audio Front Tweeter Size: 3/4″ Tweeters
Car Audio Front Tweeter Depth: 1″
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Car Audio Front Speakers Size: 6 1/2″ Speakers
Car Audio Front Speakers Depth: 5″
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue
Car Audio Rear Speakers Size: 6 1/2″ Speakers
Car Audio Rear Speakers Depth: 5″
Have any questions about our How To Install a GMC Sierra Radio DIY Guide? Leave them below and let us know!
Hi i have 08 sierra 1500 i just bought it somebody took out original radio,and put in a navi touch screen had all the bells and whistles nothing works, took it out the wiring is a rats nest next to radio is a can bus decoder,no idea what it is.i don’t see a amplifier any where i want to put in a pioneer deh s1200ubcd a simple stereo,i got 2 wire blocks coming off wire harness,can somebody tell what i need for this?the wire harness coming off radio does not match any color code on your site.thank you buster PS if i could send picture of harness you would understand
Hi Buster, thanks for commenting.
Is your factory harness completely cut up or modified? Post some pictures up so I can see the damage.
2012 Silverado WT no onstar.
Dark green 12v switch does not deliver full 12v. Won’t turn the radio on.
Bought this from a dealership that had already replaced the radio (they used it as a parts running truck for 20k) and they had installed the radio with a Scosche GMLAN adaptor for a truck with onstar. Looking at factory wiring, truck never had onstar. The door chime speaker in the LAN box shorted and was causing a draw that was killing batteries so I removed it and hard wired everything according to your notes above. Everything seems perfect, only that dark green wire (separate from one that drives RF-) does not deliver 12v on key on, it does deliver some voltage but not enough to turn the Alpine radio on. Any input would be appreciated!! Please email me if you can!!
Hey John, sounds like you’ve been through one heck of a journey! Glad my Sierra stereo wiring guide helped, but if you are not getting 12v at the switch, what voltage are you getting? Have you tried to tee into your ignition switch for switched 12v instead?
Que tal, tengo una 08 gmc sierra y los terminales de fabrica fueron cortados, y no tengo idea de donde va cada cable
I bought an 07 1500 none classic body it had a touch screen in with I bought it. Someone took the liberty of breaking in and stealing it I’m finally getting to replace it and it’s just an absolute nightmare. I’ve never seen anything like this…. I really need help😭
Hey there Hunter, thanks for reading
can you post some pictures of the wiring harness? did the thief cut or hack anything? is your original stereo harness intact?
Sorry to hear.. car thieves suck
It’s not letting me post a picture
email me directly, I can assist / or post it for you so it helps someone else.