MPN, manufacturer P/N, part number, OEM part number, catalogue number
The MPN is the only reliable way to name a connectivity component. Descriptions do not survive procurement. "Black 12-way sealed connector" describes hundreds of parts across TE, Aptiv, Molex, Sumitomo and Yazaki, and several of them will physically mate while failing the electrical or sealing requirement they were specified for. The MPN removes that ambiguity: it identifies one product, one revision, one plating, one colour code.
Confusion usually comes from the layers around it. A customer part number is the buyer's internal code for the same physical part. A distributor SKU is a warehouse reference, not a manufacturer identity. A series name, for example TE MQS or Aptiv GT 150, describes a family, not a specific part inside it. Colour variants and keying variants inside one family often differ by a single digit or suffix, and that digit is the difference between a part that mates and a part that does not.
Cross-references matter because manufacturers rename. Delphi connectors are now Aptiv. TE has absorbed AMP, Deutsch and Raychem catalogues. An MPN from a 2011 drawing may still be valid, may have been superseded, or may only exist as an obsolete stock item somewhere in the channel.
Harness Code works from the MPN first: it is the input to a shortage search, and where a direct match no longer exists, it is the anchor for proposing a verified alternative with the differences stated in writing.
Related terms
Connector housing
A connector housing is the moulded plastic body that holds and positions the terminals of an automotive connector. It is sold separately from the terminals and seals it accepts, so a working connection is always a matched set of housing, terminal and seal, not a single part number.
Obsolete / End-of-Life (EOL) component
An obsolete or End-of-Life component is one the manufacturer has stopped producing. It usually passes through an NRND warning and a last-time-buy window first, after which the only remaining supply is existing channel stock, excess inventory, or a qualified alternative.
Approved Vendor List (AVL) / Bill of Materials (BOM)
A Bill of Materials (BOM) is the complete list of parts and quantities needed to build a product. An Approved Vendor List (AVL) names the manufacturers and suppliers a buyer is permitted to source those parts from. The BOM says what; the AVL says from whom.