Mercedes W205 Battery Electrical Wiring Harness Ground Line A2055405790

Battery wiring harness with ground cable for Mercedes W205 is an original electrical system component designed for professional servicing of the power supply system in vehicles of this series. Thanks to its factory design, it ensures a stable ground connection and proper cable routing in the engine bay and around the battery, which translates to seamless operation of electronic systems. This is a practical solution for workshops and users looking for a proven component to repair or replace the factory harness.

Specifications and technical data

• SKU: rhd-A2055405790
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2055405790
• Substitutable numbers: A2055405790, A 205 540 57 90
• Category: Wiring Harnesses, Cables & Connectors

Purpose and Function in the Vehicle's Electrical System

The presented harness belongs to the Cables, Harnesses, and Connectors group and is responsible for routing the battery power line and the ground cable in the body of the Mercedes C-Class W205 generation. This element connects the battery to the vehicle's electrical system, ensuring appropriate cable cross-sections, correct mounting points, and safe cable routing in critical body areas.

A properly selected battery and ground harness is crucial for:

• voltage stability throughout the vehicle's electrical system,
• proper engine starting and operation of comfort systems,
• reducing voltage drops and interference with sensitive electronics,
• maintaining the factory cable routing and ground points.

Construction and Fit for Mercedes W205

The harness was designed by Mercedes specifically for the electrical architecture of the W205 model, taking into account the battery placement, ground points, and factory mounting brackets. This means that the cable lengths, connector types, and cable routing methods are consistent with solutions used on the production line.

This precise fit allows for:

• installation without modifying the existing system or adding extra cable sections,
• maintaining the original cable routing geometry, which reduces the risk of chafing and damage,
• a secure ground connection at points designated by the vehicle manufacturer.

Benefits of Using an Original Harness

Using the factory battery and ground cable harness in a Mercedes W205 maintains the integrity of the entire electrical system. An original component from the Cables, Harnesses, and Connectors group minimizes the risk of starting problems, control unit errors, or unstable operation of power consumers resulting from incorrect connections or excessive voltage drops.

The main advantages of this solution include:

• Compatibility with the factory electrical system – the harness is prepared to work with original connectors and mounting points.
• Safe cable routing – reduces the risk of short circuits, overheating, and mechanical damage to insulation.
• Consistency with service documentation – facilitates future diagnostics and repairs, as the wiring layout matches the manufacturer's diagrams.

Condition and Service Application

The item is offered as a used part, making it an attractive option for workshops and users seeking an economical yet factory-compliant repair solution. Replacing the battery and ground cable harness is particularly recommended in cases of mechanical damage, signs of overheating, connector corrosion, or problems with vehicle starting and power supply.

In practice, installation involves removing the old harness, cleaning the ground points, and installing the new component in the existing brackets and guides, following the connection order according to Mercedes service documentation.

If you are planning a comprehensive repair or upgrade of the electrical system area in your Mercedes and need other components from the same group, such as power cables, engine bay harnesses, or system connectors, check the available parts in the Mercedes Cables, Harnesses, and Connectors category.

For those interested in the broader use of second-hand components in the automotive industry, including in premium German brands, an article describing a practical approach to repairs and modifications using used parts may be helpful – you can find it here: Audi on second-hand parts – tuning and repairs without quality loss.