What is the definition of the 4 wires in a reverse camera?
4 Answers
DC power plug connects to the reverse light, generally only the red wire is connected, along with the red wire on the RCA plug, providing the signal for reverse video switching to the head unit. The RCA connector transmits the video signal from the camera to the head unit. Below are detailed introductions about reverse cameras: 1. Selection of reverse cameras: (1) For passenger cars, consider the camera model (optional waterproof and night vision features), screen size (3, 5, or 7 inches), and power supply voltage (12V). For large vehicles like trucks and buses, 24V is sufficient. (2) For large vehicles, selection should be more cautious. The operating conditions of large vehicles differ significantly from passenger cars. For example: harsh driving environments on construction sites, extreme temperatures, high frequency of reverse gear usage, and long working hours. Large vehicles typically use a 24V power supply, so reverse cameras designed for passenger cars cannot be used. Therefore, when selecting a product, ensure it is the right fit rather than being influenced by price or other factors. 2. Considerations: When choosing a reverse camera, ensure compatibility with your vehicle model by evaluating the camera model, power supply voltage, screen size, waterproofing, shock resistance, and anti-interference capabilities.
The four wires of my reversing camera are the power positive, power negative, video signal, and video ground. The power positive is usually the red wire, connected to the power supply of the reversing light, activating the camera when shifting into reverse gear. The power negative is black, connected to the vehicle's grounding point to ensure current flow. The video signal wire is typically yellow, connected to the input port of the host display to transmit image data. The video ground is often the shielding layer or another grounding wire, used to reduce signal interference and ensure clear images. I remember when I installed the camera myself, swapping the video signal and ground wires caused screen distortion, which took me quite a while to fix. For testing, using a multimeter to measure voltage is convenient—the power wires should show the vehicle's voltage (around 12V) when in reverse. It's advisable to reinforce the connectors with tape to prevent loose or rusty cables, which can cause short circuits in rainy weather. Regularly checking these wires can extend the camera's lifespan, saving the hassle of replacing it. From a DIY perspective, understanding the principle of these four wires makes self-installation both cost-effective and reassuring.
As an experienced auto mechanic, the four wires of a rearview camera are the positive power, negative power, video signal, and video ground. The positive power connects to the reverse light's positive power supply to energize the camera during operation; the negative power is responsible for grounding, providing a stable current loop; the video signal wire transmits image data to the display device; the video ground wire mainly serves to resist interference. In practice, many people confuse the video signal and ground wires, resulting in no display or blurry images. I recommend using color labels to mark the wire ends—typically red for positive, black for negative, yellow for signal, and the shielded layer for video ground. During installation, ensure the wiring avoids engine heat sources to prevent aging. Common faults include cable wear leading to open circuits, especially near the wheel hubs, so protective sleeves should be added. For testing, use a diagnostic tool to check the signal path—the simplest method is to try a new cable. Regular maintenance checks can prevent sudden camera failure; don't overlook this detail for driving safety.
My rearview camera has four wires: the positive power wire (positive pole), the negative power wire (negative pole), the video signal wire, and the video ground wire. The positive wire is usually red and connects to the car's reverse light power supply; the negative wire is black and is grounded to the car frame; the signal wire is yellow and transmits to the display screen; the video ground wire is the shielding layer, which reduces interference. As an average car owner, I was worried about damaging the car by connecting the wires incorrectly when installing the camera, so I had a professional shop assist me. After their explanation, I understood the function of each wire: if the signal wire isn’t connected, the image won’t display, and incorrect power connections might burn out the camera. A simple reminder: if the wires become aged or loose, repair them immediately, as it can be very dangerous when reversing. Safety first—regularly check the condition of these four wires.
