Cabling from the cabinet head unit to the DC power supply unit

To power a car head unit from a DC power supply, connect the PSU's +12V to the head unit's B+ and ACC lines (bridged if no CAN bus), and the PSU's GND to the head unit's ground, ensuring proper handling of CAN bus signals if present.Step-by-Step Connection1. Identify the Wires on the Head UnitB+ (Battery/Yellow wire): Provides constant 12V power.ACC (Accessory/Red wire): Powers the unit when switched on.GND (Black wire): Ground connection.ILL (Illumination, optional): Powers display dimming or lighting.If your head unit has a CAN bus decoder, it may require a separate connection to properly manage ACC signals . 2. Prepare the DC Power SupplyUse a regulated 12V DC supply capable of providing sufficient current for the head unit (typically 2–5A for Android 2DIN units).Ensure the PSU is turned off while making connections to avoid shorts or damage . 3. Connect Power and GroundConnect the +12V output of the PSU to the B+ (yellow) and ACC (red) wires. If there is no CAN bus, these can be bridged together.Connect the GND of the PSU to the head unit's ground (black wire) . 4. Handling CAN Bus UnitsIf the head unit has a built-in CAN bus decoder, do not bridge ACC and B+ if the CAN bus is connected, as this can damage the decoder.Either unplug the CAN bus connector and bridge ACC/B+, or connect the ACC line through the CAN bus decoder according to the manufacturer's instructions . 5. Optional ConnectionsIllumination (ILL): Connect to a 12V source if you want the display lighting active.Remote turn-on for amplifiers: Connect the head unit's remote output to the amplifier's remote input using a small-gauge wire.Speakers: Connect via RCA or speaker wires as per the head unit's outputs. Standard color coding is usually white/grey for front, green/purple for rear . 6. TestingTurn on the PSU and verify the head unit powers up.If the unit blinks or shuts off immediately, check ACC/B+ bridging and CAN bus connections. Some units require a short delay or proper jumper settings to initialize . 7. Safety TipsAlways disconnect the PSU from mains when adjusting wiring.Use fuses inline with the positive wire to protect the head unit.Avoid touching exposed wires while the PSU is on. By following these steps, you can safely power a car head unit from a DC power supply for bench testing or indoor use, while ensuring proper handling of ACC, B+, GND, and CAN bus signals.