Several types of connectors for car audio systems are used.
Wires with black stripe are for negative power:
They have low amperage and it is activated when radio is turned on.
ISO 10487 was created in 1995 and defines a standard for connectors for the head unit to the car's electrical system, consisting of a system of four different connectors typically used in head units for car audio.
Part 1 of the standard is dedicated to "Dimensions and general requirements" and Part 2 to "Performance requirements".
The first connector A is always present, is usually black in colour, and contains pins for power-supply, off/on (typically controlled by ignition key), optional control for a motorised antenna and so on.
The second connector B is for connecting four loudspeakers, front, rear, left and right, and is usually brown in colour.
The connector C is optional. Sometimes it appears as one 20-pin connector, often red in colour, or it may be divided into three separate connectors which may be hooked together, in which case C1 is usually yellow, C2 is usually green which C3 is usually blue in colour. The contact spacing is narrower than the other connectors, so the C connector is sometimes referred to as mini-ISO.
|1) line out left rear||4) line out left front|
|3) line out common ground||6) +12V switched (out)|
|2) line out right rear||5) line out right front|
|7) receive data||10) +12V switched (out)|
|9) chassis ground||12) remote control ground|
|8) transmit data||11) remote control in|
|13) data in (bus)||16) +12v switched (out)||19) audio left|
|15) +12v permanent (out)||18) audio ground|
|14) data out||17) data ground||20) audio right|
Note: ISO 10487 only defines the physical attributes of the connectors, not the pin/signal designations, which are manufacturer-defined. The example above is oriented towards VW vehicles only.
The connector D is for satellite navigation systems. It has 10 pins.
From 2000 and onwards, manufacturers, such as BMW, Citroen, Ford, Mercedes Benz, Peugeot, Volkswagen, Rover, Audi, Seat, Opel or Škoda have sometimes started using a 40-pin connector instead, called the Quadlock. The Quadlock connector consists of a block of 16 flat pins analogous to the two main ISO 10487 connectors. While the physical contact pins are the same, the pin allocation is not entirely the same, and the connector housing is not compatible. In addition to the 16 pins, like ISO 10487, there are minor connectors for optional equipment. They fit within the frame of the main connector, and has coding so that they cannot be interchanged. Minor connector B has 12 pins for audio output signals. Minor connector C has 12 pins for various audio sources such as CD-changers, MP3 players.
|1) right rear +||5) right rear -||9) I-bus (BMW) / Canbus+||13) antenna (out)|
|2) right front +||6) right front -||10) phone mute / (Speed Signal)||14) illumination|
|3) left front +||7) left front -||11) tel on / Canbus-||15) 12V battery|
|4) left rear +||8) left rear -||12) ground||16) 12V switched|
An automotive head unit, sometimes referred to as a deck, is a component of an automotive infotainment, which provides a unified hardware interface (mainly, the screen and buttons) for the entire system.
Antiquated names for head unit are receiver, in-dash stereo or dash stereo.Fuse (automotive)
Automotive fuses are a class of fuses used to protect the wiring and electrical equipment for vehicles. They are generally rated for circuits no higher than 32 volts direct current, but some types are rated for 42-volt electrical systems. They are occasionally used in non-automotive electrical products.ISO 7736
International standard ISO 7736 defines a standard size for car audio head units and enclosures. The standard was originally established by the German standards body Deutsches Institut für Normung as DIN 75490, and is therefore commonly referred to as the "DIN car radio size". It was adopted as an international standard in 1984.
Head units generally come in either single DIN (180 x 50 mm panel) or double DIN (180 x 100.3 mm panel) size. The depth is not standardized; as a result, some cars such as the Opel Manta / Ascona have the correct sized front aperture but will accommodate few DIN sized radios other than the original due to the shallow depth; this despite the vehicle being manufactured as late as 1988. The US standard for a DIN radio is 6.83" x 2" (although the actual 180 mm width converts to something like 7-3/32" so most people use 7-1/8" to allow for clearance) and the Double DIN sized radio is a 7" x 4". Some radios in Japanese Kei cars do not conform to the DIN standard however.Metra Electronics
Metra Electronics (Holly Hill, Florida) is an American automotive electronics company established in 1949, specializing in audio electronics systems and 12 volt accessories.Vehicle audio
Vehicle audio is equipment installed in a car or other vehicle to provide in-car entertainment and information for the vehicle occupants. Until the 1950s it consisted of a simple AM radio. Additions since then have included FM radio (1952), 8-Track tape players, Cassette Players, CD players (1984), DVD players, Blu-ray players, navigation systems, Bluetooth telephone integration, and smartphone controllers like CarPlay and Android Auto. Once controlled from the dashboard with a few buttons, they can now be controlled by steering wheel controls and voice commands.
Initially implemented for listening to music and radio, vehicle audio is now part of car telematics, telecommunication, in-vehicle security, handsfree calling, navigation, and remote diagnostics systems. The same loudspeakers may also be used to minimize road and engine noise with active noise control, or they may be used to augment engine sounds, for instance making a smaller engine sound bigger.