waterproof vs non-waterproof connector, IP-rated connector, environmental vs interior connector
The distinction is about location, not quality. Unsealed connectors live in the cabin: instrument cluster, body control modules, interior lighting, seat electronics. They are smaller, cheaper, easier to assemble and perfectly adequate where water never reaches. Sealed connectors live everywhere else: engine bay, chassis, doors, wheel arches, exterior lighting, anything exposed to spray, condensation, salt or steam cleaning.
Most connector families exist in both forms, and this is where substitution goes wrong. TE AMP Superseal 1.5 and TE MQS overlap in terminal thinking but not in environment. Within a single family, the sealed and unsealed housings often take different terminals and always take different accessories. A sealed housing needs a wire seal per circuit and a plug per empty cavity; an unsealed one needs neither. Swapping in an unsealed housing because it is the variant available on the shelf will pass the fit check and fail the vehicle.
Ratings should be read precisely. IP67 means temporary immersion. IP69K means high-pressure, high-temperature washdown, which is a different test and a different requirement, common on commercial and off-highway vehicles. A connector rated for one is not automatically rated for the other, and the rating only holds if the connector is fully populated and correctly assembled.
When a sealed part is unavailable, Harness Code proposes alternatives within the same environmental class, and states the rating, the terminal and the seal references so the buyer can check the substitution against the drawing rather than trust it.
Related terms
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.
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.
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.