The GMC Sierra is the sister truck of the Chevy Silverado and combines rugged styling and work truck features. Swapping out the manufacturer's stereo for an aftermarket head unit with upgraded features provides clearer sound and deeper bass in your GMC Sierra. Changing out the stereo is a quick project if you have the right parts.
Open the hood and disconnect the negative battery cable. Secure the cable so it doesn't come in contact with any metal parts.
Pry the upper left edge of the dash panel, behind the steering wheel, until the clip unsnaps. Continue pulling out the clips by working along the bottom of the panel, stopping at the center console. Pull the upper right corner of the panel and unsnap the remaining clips, remove the panel and set it out of the way.
Lower the two levers, one on each side of the stereo, and pull the radio out of the GMC Sierra dash. Unhook the wires from behind the radio and let them hang from the dash.
Connect the wiring harness adaptor to the original harness and the GM antenna adaptor to the antenna wire.
Insert the new stereo into the GM radio mounting kit and attach the wiring harness adaptor and antenna wire to the back of the unit. Slide the entire assembly into the dash and raise the side levers to secure it in place.
Reconnect the negative battery cable and turn the radio on. Test the system to ensure the controls and speakers are functioning properly. Snap the front dash panel into place starting at the lower right corner.
