You will need
- - soldering iron;
- - solder;
- - wires.
If the car normally, then maybe she has a built in AUX input. To connect AUX – external audio source, find the pin-out connections. Look for three pins on the plug connector for the head unit, responsible for the incoming signal to the left and right channel.
To make sure that you have disconnected those wires, turn on the unit and individually touch each wire. Increasing the volume, you will hear a hum in the speakers. Do not be afraid that you will hit the current in the circuit low voltage, so your hands are not in danger.
Solder wires to connectors of type RCA (this will allow you later to connect to the car stereo using adapters for different devices), or directly solder the connector from the headphones.
Do line input can be somewhat different: open the radio and look at its diagram of all the notes, which are responsible for wired Line-in. They are, as a rule, and are marked: Line GND Line-R Line-L. to Check whether you have defined "purpose" of a contact by touching each contact finger.
Often on printed circuit boards have contacts provided for the line input. Find these contacts, solder to them wires and connectors to connect devices using adapters.
Can also find the inputs of the sound signal directly on the chip amp. But first, understand the nature of the work: from the source signal supplied to the amplifier and to the external outputs. Often all of these devices are assembled on a single Board, but there are also times when the amplifier is brought to a surcharge.
Look at the diagram of the receiver capacitors and around these electronic components, solder the wire needed to connect the external device. To verify the correctness of desoldering you can, again, method of testing, i.e. Patronuses finger to each wire.
Follow safety rules, working with a soldering iron!
Note: if the connecting line runs directly to the amp (no preamp), the more you will be able to regulate the volume and filter settings.