Mercedes R129 W202 Relay Green Control Unit 12V 30A A0045450405

Mercedes R129 W202 Relay Green Control Unit 12V 30A is an original component from the Relays category, designed for the electrical systems of Mercedes vehicles. The green housing allows for quick identification in the fuse box, and the current parameters ensure stable operation of loaded 12 V circuits.

Specifications and technical data

• SKU: A0015429619
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0015429619
• Substitutable numbers: A0015429619, A 001 542 96 19
• Color: Green
• Category: Relays

Application and function in the electrical system

The relay used in Mercedes R129 and W202 series models is responsible for reliably switching higher-current circuits when controlled by low-current signals from electronic modules or switches. This relieves the load on more delicate control elements and stabilizes the operation of key components in the 12 V system.

This type of solution is used, among others, in power circuits for comfort modules, auxiliary systems, or selected engine components, where reliable and repeatable load switching is required while maintaining an appropriate current reserve.

Design, color coding, and identification

The characteristic green housing makes it easy for service technicians and users to quickly locate the correct component in the relay box. The color is often used in factory Mercedes installations as a visual distinction for relay types, which reduces the risk of errors during diagnostics or replacement.

The relay housing is designed for installation in standard sockets used in Mercedes vehicles, allowing for secure seating in the base and a stable connection to the wiring harness. The construction is resistant to typical operating conditions in the engine compartment or inside the vehicle, such as temperature changes or vibrations.

Benefits of using an original Mercedes relay

Using a relay dedicated to specific Mercedes models allows for maintaining the consistency of electrical parameters with the factory installation design. Properly selected current and voltage values reduce the risk of contact overheating, voltage drops, and unstable operation of electrical consumers.

The main advantages include:

• Compatibility with Mercedes installations – perfect fit for factory sockets and electrical diagrams.
• Stable switching of higher-load circuits in 12 V systems.
• Clear identification thanks to the distinctive green housing.
• Suitable for use in diagnostics and repairs as a component compliant with the vehicle manufacturer's specifications.

Component condition and service application

The relay is a dismantled part intended for service applications in Mercedes vehicles where maintaining the original electrical architecture is required. This type of component is particularly useful for repairs where matching the operating characteristics to the factory design is essential.

Thanks to its original construction, the relay can be used both as a replacement part during standard repairs and when restoring electrical systems in vehicles undergoing renovation or reconstruction according to the manufacturer's specifications.

Selection and safety when purchasing used relays

When selecting a relay for a specific Mercedes vehicle, it is crucial to compare the electrical parameters and markings with the existing component, as well as to verify compatibility with the vehicle's service documentation. Proper selection minimizes the risk of circuit overload and ensures correct cooperation with control modules.

If you want to streamline the process of selecting components from this group and avoid common mistakes when buying second-hand parts, use the practical tips included in the guide Safe purchase of used car parts online – a step-by-step guide.

If you are planning a comprehensive repair or upgrade of the electrical system in your Mercedes and need other elements from the same group, such as power relays, light relays, or auxiliary system relays, check the available parts in the Mercedes Relays category.