Mercedes W176 W204 W207 W166 Relay 4 Pin Grey Hella SET X2 A0025428719

Mercedes W176 W204 W207 W166 Relay 4 Pin Grey Hella SET X2 is a set of two components from the Relays category, designed for installation in selected Mercedes models. These grey relays from the renowned manufacturer Hella ensure stable electrical circuit switching and are an appropriate choice for servicing power supply, control, and protection systems in vehicles of this brand. By maintaining OEM specifications, they provide a practical solution for repairs and diagnostics of the electrical system.

Specifications and technical data

• SKU: A0025428719-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0025428719
• Substitutable numbers: A0025428719, A 002 542 87 19, 4RA007793, 4RA007 793
• Color: Grey
• Category: Relays

Application and function of the relays

The set of grey Hella 4-pin relays is designed for use in the electrical systems of Mercedes W176, W204, W207, and W166 series vehicles. These components are responsible for safely disconnecting and connecting high-current circuits when controlled by a low-current signal from electronic modules. They are used, among other things, in power supply circuits for consumers, comfort module control, or auxiliary systems, where consistent performance and load resistance are required.

The grey housing facilitates identification of the relay type in the fuse box or relay module, which is important for diagnostics and quick replacement in workshop conditions. The use of a standard 4-pin layout allows for installation in factory sockets without the need for wiring modifications.

Design and construction features

The relays feature a four-pin contact configuration, typical for many control circuits in Mercedes vehicles. This design ensures simple integration with the existing installation and predictable behavior in systems where OEM components were originally used. The grey housing is made of plastic adapted for operation in relay compartments and fuse boxes, where variable temperatures and vibrations occur.

The internal contact and coil layout is designed to ensure stable switching at typical automotive supply voltages. As a result, the relays perform well both in daily operation and under conditions of increased electrical load.

Benefits of using original Mercedes relays

Using relays that comply with factory specifications in Mercedes vehicles offers a number of practical benefits:

• Compatibility with the installation – perfect fit for factory sockets and control systems in W176, W204, W207, and W166 models.
• Repeatable operating parameters – predictable behavior in circuits responsible for power supply and control.
• Reduced risk of electrical errors – lower probability of incorrect switching compared to generic replacements.
• Simplified diagnostics – standard pin layout and recognizable housing color.

The set of two relays allows for the simultaneous replacement of a pair of components in critical circuits or keeping one unit as a spare, which is beneficial from the perspective of vehicle maintenance and operational readiness.

Product condition and service application

The offered relays are in used condition, making them an economical solution while maintaining compliance with Mercedes factory specifications. Such components are often chosen by workshops and individual users who want to reduce repair costs while maintaining the original architecture of the vehicle's electrical system.

The relays will work well both as replacements for damaged components in existing circuits and for reconfiguring relay boxes during major service work. Thanks to the standard 4-pin design, installation is straightforward for an experienced automotive electrician or mechanic.

System expansion and additional information

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 additional relays, control modules, or circuit protection elements, check out the available parts in the Mercedes Relays category.

To better plan service work and reduce vehicle downtime in the workshop, it is worth checking out practical tips regarding the use of used OEM parts – these are discussed in detail in the article Availability of car parts on demand vs. repair time – how do used OEM parts shorten workshop stays?.