This BSM (engine bay fuse/relay/control unit) manufactured by Delphi provides centralized power distribution and control for a range of electrical circuits on Stellantis Citroën and Peugeot models. It is commonly identified by part numbers 9661087080, 6500CK and reference L11-00 — codes often used by professionals and DIYers when searching for a replacement. The unit integrates fuse and relay functions and supplies power to starters, ignition circuits, fuel pump relays and other essential engine-bay systems; a functional BSM is critical for reliable vehicle starting and electrical safety.

Fitment And Compatibility

Designed for a number of Citroën and Peugeot vehicles from the 2000s era that use the BSM L11-00 specification. Example application: Peugeot 307 (check the stamped part numbers 9661087080 / 6500CK / L11-00 against the part currently fitted). When searching, include OEM codes to improve match probability.

How To Replace

Intended for experienced mechanics and competent DIYers. Typical replacement steps:

• Disconnect the negative battery terminal and wait a few minutes to discharge capacitors.
• Locate the BSM in the engine bay (usually close to the battery or main fuse area) and remove the protective cover.
• Note and mark connector positions, then carefully unplug all wiring harness connectors.
• Unscrew or unclip the unit from its mounting points. If plastic tabs are damaged, this often does not affect electrical function but replace mounting hardware if required for secure fixing.
• Install the replacement unit, reconnect harnesses ensuring correct seating, restore protective covers and reconnect the battery.
• Verify all related systems (starter, lights, immobiliser indicators, fuel pump) operate correctly after installation.

Installation Recommendations

Always follow vehicle manufacturer procedures. Recommendations:

• Disconnect battery negative before starting to avoid shorts and potential damage to the unit.
• Inspect connector pins and harness seals for corrosion or water ingress; clean or replace as needed.
• Secure the unit mechanically to avoid vibration stress; damaged mounting tabs do not usually affect electrical performance but should be repaired for long-term reliability.
• After installation, check fuses and relays associated with the BSM and perform a functional test of all circuits it feeds.
• Use basic diagnostic equipment (multimeter) to confirm power and ground presence if systems do not operate immediately.

Most Common Failure Causes

Reasons BSM units fail or are removed for replacement include:

• Moisture ingress and corrosion of connector pins or internal printed circuit traces.
• Thermal cycling and age-related degradation of electronic components.
• Electrical overcurrent events or voltage spikes (bad alternator, jump-start incidents).
• Mechanical damage to connectors or housings from accidents or improper handling.
• Faulty relays or burned tracks inside the module due to repeated short circuits.

Technical Information

• Manufacturer: Delphi
• Model: BSM L11-00
• Product Codes: 9661087080, 6500CK, L11-00
• Other Numbers: 9661087080 / 6500CK (use these when searching by part number)

Note: The unit description above states the module has been tested and is fully functional. Cosmetic or mounting-tab damage may be present but does not affect electrical performance.