Step 3: Connecting the Components Together
Solder two wires on the stereo adapter, one in the front (ground) and one at the very left /right back (it doesn't better which side since it is a mono speaker).
Solder other components together as shown in the 2nd diagram. Remember to leave out red wire of the battery snap for the rocker switch.
Solder the red wire of the battery snap to the rocker switch. Solder another wire that connects the rocker switch and the positive terminal of the amp module.
If you don't understand the steps above . Look at the next step to see how the circuit is connected.