Installing an amplifier and sub-woofer in your 2003 Chevy TrailBlazer is one of the best ways to improve the sound quality of your stereo system. To properly install the amp and sub-woofer, you will need the correct tools and steps. You can purchase everything that you need to wire and install the amp and sub at your local car audio store. You can do the job at home but be prepared to spend about two hours on it.
Remove the screws that secure the dashboard to the frame of the TrailBlazer with a screwdriver. The screws will be on the passenger's side of the dashboard where it meets the doors and inside the glove box. Once the screws have been removed, pull the dash away from the frame on the passenger's side to expose the rear of the stereo receiver.
Open the rear door of the TrailBlazer and place the amp and sub in the trunk. Cut a piece of speaker wire that is long enough to run from the amp to the sub-woofer. Strip both ends of the wire 1/4 of an inch from the tips with wire strippers. Insert one end of the wire into the connections on the rear of the sub and insert the opposite end of the wire into the corresponding connections on the amp: the positive (+) with the positive and the negative (-) with the negative. Tighten the connections on the amp with the screwdriver.
Cut a piece of speaker wire long enough to run from the amp to the rear of the stereo receiver with the wire cutters. Cut a section of 10-gauge wire to run from the amp through the fire wall and to the battery. Use the wire strippers to strip the ends of the wires 1/4 of an inch from the tips.
Insert the speaker wire into the connection on the amp labeled "Lead" or "Remote Lead" and tighten the connection on the amp with the screwdriver. Insert one end of the 10-gauge wire into the connection on the amp labeled "Power" and tighten the connection with the screwdriver.
Guide the remote lead and power wires to the front of the stereo receiver at the lower edge of the door frames. Tuck the wires under the plastic panel along the way to the front of the receiver. Connect the speaker wire to the connection on the rear of the stereo labeled "Lead" or "Remote Lead." Tighten the connection with the screwdriver.
Replace the dashboard, then reinsert and retighten the screws. Pull the floor carpet back off the frame and remove the rubber plug from the fire wall. Guide the power wire through the hole in the fire wall. Open the hood and pull the power wire up to the battery. Make sure that the wire cannot touch any components on or around the engine that are hot.
Insert the end of the power wire into the connection on the fuse and tighten the connection with the screwdriver. Place the fuse on the top of the positive battery connection and tighten the screw on the side of the fuse to secure the fuse to the battery.
