The connector and sourcing terms a harness buyer actually has to get right.
Plain, self-contained definitions of the parts, standards and sourcing terms behind a wire harness BOM. Written for the person who sources these components for a living.
Send us a part numberEvery term, defined
Allocation and lead time
Allocation is when demand for a component exceeds supply and the manufacturer rations output across customers instead of quoting freely. Lead time is the interval between placing an order and receiving it. When a part goes on allocation, its lead time stretches and stops being a promise.
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.
Backshell and strain relief
A backshell is an accessory fitted to the rear of a connector to route and clamp the exiting wires. It provides strain relief, so mechanical load on the harness is carried by the housing rather than by the crimped terminals, and it usually sets the exit angle.
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.
Contact plating (tin vs gold)
Contact plating is the metal coating on a terminal's mating surface, most often tin or gold. Plating decides contact resistance, corrosion behaviour and how many mating cycles a contact survives. Tin and gold contacts should not be mated to each other.
Counterfeit risk and verified sourcing channels
Counterfeit risk is the risk of receiving fake, re-labelled, recycled or out-of-specification components presented as genuine. It rises sharply for parts that are scarce, obsolete or on allocation, which is exactly when buyers are forced outside their usual channels.
CPA / TPA (connector and terminal position assurance)
A TPA (Terminal Position Assurance) is a secondary lock that confirms every terminal is fully seated in its cavity. A CPA (Connector Position Assurance) confirms two connector halves are fully mated and latched. Both are error-proofing parts, and both are separate part numbers.
Crimp and crimp height
A crimp is the cold-formed mechanical and electrical joint between a terminal and a wire. Crimp height is the measured height of the finished conductor crimp, and it is the main control on whether that joint survives vibration and temperature cycling in service.
Cross-reference and drop-in equivalent
A cross-reference maps one manufacturer part number to a comparable part from another family or another manufacturer. A drop-in equivalent is a cross-reference matching on form, fit and function, usable without any change to the harness, the tooling or the mating half.
Date code and lot code
A date code shows when a component was manufactured, usually as a year and week. A lot code identifies the production batch it came from. Together they let a buyer trace a part back through the supply chain and check that stock is genuine, recent and consistent.
Franchised vs independent distributor
A franchised or authorised distributor holds a contract with the manufacturer and buys directly from the factory. An independent distributor has no such contract and sources from the open market: excess inventory, other distributors, and stock outside the manufacturer's direct channel.
IP rating (ingress protection)
An IP rating is a two-digit code defining how well a connector or enclosure resists solid particles and water. The first digit covers solids and dust, the second covers water, so IP67 means dust-tight and protected against temporary immersion.
Keying and polarization
Keying, or polarization, is the mechanical feature that stops a connector being mated the wrong way round or into the wrong mating half. Coding variants and colour coding distinguish otherwise identical connectors so a harness cannot be assembled or serviced incorrectly.
Lead time and on-order
Lead time is the interval between placing an order and receiving the goods. On-order stock is stock a supplier has already purchased but not yet received. A quoted lead time is a forecast, and under allocation it is a forecast that moves.
Manufacturer Part Number (MPN)
A Manufacturer Part Number (MPN) is the unique code a component maker assigns to one exact product variant. In automotive connectivity, the MPN fixes housing, cavity count, keying, colour and plating, so two parts with different MPNs are not interchangeable even if they look identical.
Mating cycles
Mating cycles are the number of times a connector can be mated and unmated while still meeting its electrical specification. The rating depends mainly on contact plating and contact normal force, and it is usually far lower than buyers assume.
Minimum order quantity (MOQ)
Minimum order quantity (MOQ) is the smallest quantity a supplier will sell of a given part. It is usually set by the packaging unit, a reel or a bag, and it can force a buyer to purchase far more material than the shortage actually requires.
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.
Open market / broker sourcing
Open market sourcing means buying components outside the manufacturer's authorised channel, from excess inventory, other distributors and stockholders. It is often the only route to a part that is obsolete or on allocation, and it carries a verification burden the authorised channel does not.
Pin and socket (contact gender)
Pin and socket describe the two halves of an electrical contact. The pin, also called male, tab or blade, enters the socket, also called female or receptacle. Contact gender is fixed by the connector housing and by the circuit's function, not by the wire.
RoHS and REACH compliance
RoHS restricts hazardous substances such as lead, cadmium and hexavalent chromium in electrical products. REACH is the EU chemicals regulation, including a candidate list of substances of very high concern that suppliers must declare above a defined threshold.
Sealed vs unsealed connector
A sealed connector uses interface seals, wire seals and cavity plugs to keep moisture and dust out, and carries an IP rating such as IP67 or IP69K. An unsealed connector has no such protection and is used only in dry interior locations.
Second source
A second source is an approved alternative supplier or manufacturer for a part, qualified in advance so production can switch without a redesign. Single-sourced parts are the ones that stop a line when their single source fails.
Suspect counterfeit and incoming inspection
A suspect counterfeit part is one whose authenticity, origin or specification cannot be confirmed. Incoming inspection is the check performed on delivery, covering documentation, packaging, labels, date and lot codes, and the parts themselves against the manufacturer drawing.
Terminal / contact
A terminal, or contact, is the metal part crimped to a wire and inserted into a connector housing to make the electrical connection. Terminals are specified by family, gender (pin or socket), wire cross-section range, and plating, typically tin or gold.
USCAR and LV214 (automotive connector test standards)
USCAR-2 and LV214 are the two dominant automotive connector qualification standards. USCAR-2 is the North American specification from the US Council for Automotive Research; LV214 is the German OEM specification. A substitute part has to carry the standard the drawing names.
Wire gauge (AWG and mm2 cross-section)
Wire gauge describes a conductor's cross-sectional area. European automotive drawings state it in square millimetres, for example 0.35, 0.5, 0.75. American drawings use AWG, where a higher number means a thinner wire. The two systems do not map onto each other exactly.
Wire seal and cavity plug
A wire seal is a rubber grommet crimped with the terminal that seals the gap between the wire and the connector cavity. A cavity plug seals an unused cavity. Together they give a sealed connector its rated ingress protection; a single missing seal voids it.