[. . . ] If the sound distorts when the volume is turned up, turn the bass level control counter-clockwise. When using with an RCA equipped car stereo (standard output of 500 mV), set to the NORMAL position. Output of 4 V or more, adjust level to match the car stereo output level. If you hear a beat while listening to an MW/LW broadcast with your car stereo, change the BFC switch using a small standard tip screwdriver. [. . . ] Do not route wires where they will get hot, for example where the heater will blow over them. If the insulation heats up, it may become damaged, resulting in a short-circuit through the vehicle body. Make sure that wires will not interfere with moving parts of the vehicle, such as the gearshift, handbrake or seat sliding mechanism. Never feed power to other equipment by cutting the insulation of the power supply wire to tap from the wire. Never replace the fuse with one of greater value or rating than the original fuse. Use of an improper fuse could result in overheating and smoke and could cause damage to the product and injury including burns. Do not ground the speaker wire directly or connect a negative (­) lead wire for several speakers. This unit is for vehicles with a 12-volt battery and negative grounding. If the car stereo is kept on for a long time while the engine is at rest or idling, the battery may go dead. If the system remote control wire of the amplifier is connected to the power terminal through the ignition switch (12 V DC), the amplifier will always be on when the ignition is on-- regardless of whether the car stereo is on or off. Confirm that no parts are behind the panel when drilling a hole for installation of the amplifier. Protect all cables and important equipment such as fuel lines, brake lines and electrical wiring from damage. Install tapping screws in such a way that the screw tip does not touch any wire. This is important to prevent wires from being cut by vibration of the car, which can result in fire. To prevent electric shock, do not install the amplifier in places where it might come in contact with liquids. To ensure proper installation, use the supplied parts in the manner specified. If any parts other than the supplied ones are used, they may damage internal parts of the amplifier, or they may become loose causing the amplifier to shut down. Never replace the fuse with one of greater value or rating than the original fuse. Use of an improper fuse could result in overheating and smoke and could cause damage to the product and injury including burns. Example of installation on the floor mat or on the chassis Insert the supplied tapping screws (4 × 18 mm) into the screw holes. [. . . ] Example of installation on the floor mat or on the chassis Insert the supplied tapping screws (4 × 18 mm) into the screw holes. Push on the screws with a screwdriver so they make marks where the installation holes are to be located. To ensure proper heat dissipation of the amplifier, be sure of the following during installation. Do not install the amplifier on unstable places such as the spare tire board. [. . . ]