Relay Mercedes W163 W169 W203 W210 Relay Unit 5-Pin Yellow Tyco A0025421419

Mercedes W163 W169 W203 W210 5-Pin Yellow Tyco Relay is an original part from the Relays group, designed for use in selected Mercedes models of the W163, W169, W203, and W210 class. The yellow housing marking facilitates quick identification in the fuse box, and the five-pin design ensures stable operation of the vehicle's electrical systems.

Specifications and technical data

• SKU: A0025421419-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0025421419
• Substitutable numbers: A0025421419, A 002 542 14 19
• Color: Yellow
• Category: Relays

Relay Purpose and Function

The presented five-pin relay is used in the electrical system of Mercedes cars as an intermediate element between low-current control and higher-load circuits. This relieves switches and control modules, ensuring safe activation of consumers such as various auxiliary systems, lighting, or comfort equipment, in accordance with the factory configuration of the specific model.

The yellow housing helps technicians and users quickly locate the correct relay in the fuse box, speeding up diagnostics and potential replacement. Using an original solution maintains consistency with the manufacturer's service documentation and wiring diagrams.

Construction and Design Features

The relay has five terminals, enabling more complex switching functions than simple four-pin systems. The contact and coil technology used is adapted to the requirements of Mercedes vehicle installations, ensuring adequate resistance to vibrations, temperature changes, and typical automotive current loads.

The distinctive, yellow housing color is not just a visual element – in many vehicle configurations, it corresponds to a specific type of function or operating parameters, making it easier to select the correct part during servicing. The compact form of the relay allows for installation in standard sockets within fuse boxes and distribution modules.

Benefits of Using an Original Mercedes Relay

Using a relay that complies with the manufacturer's factory requirements results in:

• stable operation of electrical systems due to correctly selected coil and contact parameters,
• maintained compatibility with the existing wiring harness and mounting sockets,
• easier diagnostics based on Mercedes service diagrams,
• reduced risk of circuit malfunction resulting from the use of aftermarket parts with uncertain parameters.

Relays from this series are frequently used in workshops specializing in the Mercedes brand, as they help maintain the electrical system's consistency with solutions provided by the vehicle manufacturer.

Condition and Service Application

The offered part is from the used parts group, making it an attractive cost-effective solution while maintaining the original manufacturer's specifications. These types of relays are often used in diagnosing electrical faults – both as a replacement part for testing and as a final installed part after compatibility is confirmed.

In most cases, replacing the relay involves removing it from its socket and inserting the new part, without interfering with the wiring harness. This makes the operation quick and requires no special tools, provided access to the fuse box is ensured according to the vehicle's service manual.

System Expansion – Other Mercedes Relays

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

Additionally, if you want to deepen your knowledge on selecting original components and working with OEM numbers in the context of advanced powertrains, it is worth reading the article describing Audi's five-cylinder engines and practical tips for selecting used parts – you can find it here: Audi Five-Cylinder Engine – Legend and Selection of Used OEM Parts.