Description
Overview
This listing is for a used Delphi BSM B2 engine fuse and relay box for PSA vehicles. The unit is guaranteed functional. Some plastic mounting tabs may be damaged — this does not affect electrical performance.
Function and Common Symptoms
The BSM (Boîtier de Servitude Moteur) is the engine bay fuse and relay distribution box. It supplies and switches power to critical circuits such as the fuel pump, radiator fan, headlights, wipers and various actuators. A failing BSM commonly causes intermittent electrical failures, an inoperative fuel pump, a continuously running radiator fan, blown fuses or lighting outages.
Causes and Durability
Failures are typically caused by water ingress, connector corrosion, thermal stress, vibration and internal relay or fuse wear. Longevity depends on vehicle use and environment; units on older Peugeot 206 and 307 models are more likely to fail after years of service, especially in cars exposed to moisture or battery leaks.
Installation
The BSM is located in the engine bay near the battery. Replacement is generally plug-and-play: disconnect the negative battery terminal, release fuse and connector clips, unplug the multi-pin harnesses, remove the old unit from its bracket and fit the replacement. Ensure connectors fully seat. In most cases no coding or pairing is required; correct BSM type and matching product number are essential for reliable operation.
Compatibility And Fitment Advice
Common fitment includes selected Peugeot 206 and Peugeot 307 variants. Always verify compatibility by comparing the part number, BSM designation (B2), number and shape of connectors and the fuse/relay layout. Using exact product codes 9646405180 / 6500.Y1 / 6500 Y1 and the BSM B2 marking ensures the highest chance of correct replacement.
