2025420532 Mercedes W202 Overvoltage Protection Relay – OEM Used & Tested

Descrizione

This Mercedes overvoltage protection relay is a genuine OEM electrical component for the Mercedes W202 C-Class. Primary OEM number 2025420532. It is designed to protect the sensitive control units of the car from excessive on-board voltage by switching off their supply when a dangerous voltage peak occurs, for example from a faulty charging system or a jump start with the wrong voltage. It is a plug-in relay fitted in the electrical box of this model.

Its job is to monitor the supply voltage of the protected circuits and to open the connection when the voltage rises above a safe level, so that the engine, ignition and other electronic control units are not damaged. A properly working overvoltage protection relay supports reliable protection of the electronics, a stable supply for the connected systems and correct operation of the electrical system of the car.

Common signs of a faulty unit include an engine that does not start, sudden stalling, no power to some control units, intermittent faults in the engine management, burnt or corroded contacts and a relay that no longer switches. When the relay fails, the protected circuits may lose their supply, the car may not run correctly and the electronics may be exposed to damage by voltage peaks. Such relays are known wear items in older vehicles of this generation.

This is a used original part, removed from a vehicle and tested before sale. Match the exact OEM number 2025420532 before ordering. Professional installation is recommended, and adaptation to the vehicle may be required where applicable.