How to Change a BMW Stereo Amp


1. Disconnect the grounding cable from the BMW battery. The grounding cable connects the negative lead to the chassis of the vehicle. Use a 10 millimeter wrench to loosen the cable's clamp. Remove the cable from the lead and rest it away from the negative lead post.
2. Replace the ring terminal (included in the amplifier wiring kit) on the positive lead of the battery and route the new power supply wire into the cabin. Replace the rubber grommet in the opening of the firewall to protect the wiring. Remove the fuse from the ring terminal.
3. Remove the upper dash trim at the center of the dashboard. Pry the panel free at the bottom edge using a trim panel tool. Grab the panel and pull it free. Disconnect the power supply wire connected to the hazard button on the panel.
4. Remove the two screws at the top of the lower trim panel with a Phillips head screwdriver. Pull the lower panel free from the dash. Remove the screws on either side of the stereo deck and pull the stereo from the dash far enough to reach the wire connections in the rear.
5. Pull out the signal cable and turn-on lead from the stereo. Connect the new cables (from the amplifier wiring kit) to the stereo and route them from the deck to the location of the new amp.
6. Remove the old amplifier from the vehicle. Place the new amp into the previous amp's location. Connect the power supply cable, the signal cable, the turn-on lead and speaker wires to the new amplifier.
7. Replace the BMW stereo deck into the dash. Screw the two screws into the stereo mounting bracket. Replace the lower trim panel and replace the two screws at the top. Connect the hazard power wire to the upper trim panel and replace it on the dash.
8. Place the negative battery cable onto the negative battery lead. Tighten the clamp with a 10 millimeter wrench. Place the fuse into the fuse holder on the ring terminal.