Description
BSM B2 DELPHI Engine Unit. This is a used part guaranteed to be functional. Some mounting clips may be damaged – this does not affect functionality.
Function
The BSM B2 by Delphi is the engine compartment fuse and relay box responsible for power distribution and circuit protection for numerous engine-related systems. It contains fuses, relays and associated electronics that supply power to ignition circuits, cooling fans, fuel system auxiliaries, lighting and other engine bay consumers. Correct operation of the BSM ensures stable power delivery and protection against short circuits and overloads.
Fitment
Designed for Stellantis Group vehicles including Citroën and Peugeot models. Common applications include Citroën Xsara Picasso and Peugeot 206 and 307. The unit is often searched for under part numbers 9650664180 and 6500Y1.
Replacement Procedure
Before starting any work, always disconnect the negative battery terminal and follow the vehicle manufacturer’s safety procedures. Typical replacement steps:
- Locate the BSM in the engine bay (usually protected by a plastic cover near the battery or inner wing).
- Remove the protective cover and any obstructing components to gain access.
- Carefully unplug all electrical connectors, noting or photographing their positions to ensure correct reassembly.
- Remove mounting fasteners and extract the BSM. Take care with plastic clips which may be brittle.
- Install the replacement unit, secure all fasteners, reconnect connectors and replace covers.
- Reconnect the battery and verify the operation of affected systems (lights, starter, fans, etc.).
Why The Part Fails Most Often
Common causes of BSM failure include water ingress and corrosion in connectors, thermal cycling and age-related deterioration of electronic components, electrical overloads or short circuits, and mechanical damage to plastic housings or mounting clips due to vibration. As noted, broken or damaged mounting clips are frequently observed on used units but typically do not affect electrical functionality.
Technical Information
- Manufacturer: Delphi
- Model: BSM B2
- Product Codes: 9650664180, 6500Y1
- Additional Numbers: 6500 Y1
Installation Recommendations
- Always disconnect the battery before removal or installation.
- Inspect all connector pins and wiring for corrosion or damage and clean or repair as needed.
- Replace any broken mounting brackets or clips to ensure the unit is properly secured and protected from vibration.
- Use dielectric-safe contact cleaner on electrical connectors and apply contact protection if appropriate.
- After installation, perform a full electrical check of systems powered by the BSM and clear any logged fault codes if necessary.
- If unsure about disassembly/reassembly or diagnostics, seek professional service with the proper tools and diagnostic equipment.







