A harness can have the correct wire in the correct cavity without a complete record of terminal seating and locking. For a useful quotation, specify the connector parts, the required assembly states and the evidence that demonstrates each state. “Continuity passed” and “secondary lock fitted” answer different questions.
This guide concerns removable terminals retained inside connector housings. It focuses on procurement records, rather than instructions for assembling or repairing a particular connector. The manufacturer's applicable drawing and assembly specification must govern the offered combination.
Identify which interface the lock controls
Terminal position assurance, or TPA, concerns terminals within a housing. Connector position assurance, or CPA, concerns the mating connection. Molex describes its MX150 CPA as securing the mating latch, while its terminal-retention discussion addresses lances and TPA features. These names identify different inspection targets. Molex connector contact-retention guide.
Do not assume every TPA works identically. The same Molex guide contrasts Mini-Fit secondary retention with a MicroClasp example in which terminals are retained only after its TPA is fitted. Specify the exact family and construction before deciding which intermediate assembly state is acceptable.
Record the manufacturer and complete part numbers for the housing, terminals, secondary lock and relevant seals or accessories. Include the wire specification and applicable component revisions. A matching color or cavity count is insufficient evidence of interchangeability.
Use the harness pinout and cavity-view guide to establish cavity identity. Then add separate seating and locking requirements; a cavity map identifies where a wire belongs, not whether its terminal has reached the required position.
Translate the assembly specification into inspection gates
TE's EP-II specification separates contact insertion from installation of its secondary retainer. It describes an audible or tactile insertion indication and a light pull-back check, then requires full contact insertion before the retainer is installed. These are EP-II instructions, not a universal force-setting procedure. TE application specification 114-13265, revision D, sections 3.6–3.7.
For Power CMC, Molex states that a badly seated terminal can stop TPA closure and identifies excessive closing resistance as a reason to investigate seating. A quotation should therefore identify the specified final position and the disposition when that position cannot be achieved. Molex Power CMC application specification, revision B1, sections 2.9–2.9.1.
Accessory requirements also vary. TE identifies wedgelocks as required components for all DEUTSCH DTP connectors. For a DTP proposal, the bill of materials and completion record must account for that requirement. Do not extend it to every connector family. TE DEUTSCH DTP wedgelocks.
Ask the supplier to show how the selected instructions become a controlled inspection sequence. Require any proposed alternative method to be identified for approval. Extra force, a substituted accessory or an undocumented adjustment should not become the informal solution to a failed gate.
Specify three separate kinds of evidence
Seating confirmation, lock-position confirmation and retention-force evidence are distinct records. Their acceptance criteria should identify what was checked, on which configuration and at what assembly stage.
A light assembly check does not establish a quantified retention rating. Likewise, a laboratory result for a named configuration does not prove that every shipped cavity was inspected. Keep process coverage and qualification evidence separate in the RFQ.
On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.
| RFQ inspection item | Evidence to request | Question to resolve before acceptance |
|---|---|---|
| Part combination | Housing, terminal, lock and wire identities linked to the drawing revision | Does the evidence cover the offered combination? |
| Terminal seating | Defined indication or inspection method, cavity coverage and assembly stage | Which populated cavities were checked? |
| Secondary-lock completion | Specified final-position reference and recorded result | Is the lock fully positioned, rather than merely present? |
| Quantified retention evaluation | Test method, specimen configuration, lock state, results and acceptance basis | Does it evaluate the required interface and condition? |
| Test-fixture contact | Fixture identity, maintenance status and applicable interface requirements | Could inspection equipment affect the terminal? |
| Rework release | Affected cavity, disposition, replacement identities and repeated checks | Does the final record cover the assembly as shipped? |
These are proposed purchasing fields. Agree the recording format and sampling plan before ordering; the table does not assert a mandatory standard or an existing supplier capability.
Keep electrical and mechanical results separate
A continuity result reports an electrical condition under the stated test conditions. It does not, by itself, demonstrate that the terminal-retention mechanism satisfies its mechanical requirements. Request both records where both are required; avoid relabeling one result to close the other requirement.
For a quantified retention evaluation, ask what load is applied to which interface, how the specimen is restrained, whether the secondary lock is open or closed, and what conditioning applies. Identify the specified loading rate, acceptance criterion and failure definition. A result with the lock engaged should not silently stand in for a requirement evaluated without it.
Do not insert a generic pull value into the drawing. Have engineering identify the applicable manufacturer's specification or an approved application-specific method. Record whether evaluated specimens may be released afterward or must be excluded from shipment.
The test fixture also needs control. Molex's Power CMC specification warns that incorrect continuity-fixture geometry and unsuitable probes can damage terminals. This supports requesting fixture compatibility evidence; it does not establish universal probe dimensions. Molex Power CMC specification, section 2.16.4.
Audit a fictional supplier's inspection coverage
The following is a fictional purchasing exercise, not a customer case or validated assembly. Order H-047 calls for 40 harnesses. Each has one 12-cavity connector with eight populated positions. The drawing separately identifies the four unpopulated positions and their required treatment.
Supplier A offers 40 electrical pass records and one photograph showing a fitted secondary lock. The photograph can illustrate an appearance, but it does not establish inspection coverage across the order. The electrical records also leave terminal seating and lock-position coverage unresolved.
Supplier B identifies all 40 assemblies and records eight seating checks per assembly, plus the required lock-completion result. That accounts for 320 declared seating checks. The count shows coverage against the proposed plan; it does not prove that the inspection method detects every possible defect.
B also submits a quantitative retention report covering three specimens. Those three results remain sample evidence. They should not be described as 320 retention-force measurements, and their relevance still depends on the tested parts, lock state, method and acceptance criteria.
Two assemblies were subsequently reworked. Before release, request the affected cavity identities, repair disposition and required repeat-inspection results. Preserve the earlier failures or superseded results. Counting a retest as an additional shipped harness would conceal the difference between inspection events and unique accepted assemblies.
Define the final release record and change triggers
Tie the accepted records to the harness revision, component identities, inspection instruction and lot or serial range. Where results are recorded at lot level, document how the supplier demonstrates coverage and contains affected material after a failure. A photograph should identify its specimen and viewing direction; it is not automatically evidence for an entire batch.
For terminal removal or replacement, request the applicable service instructions and allowed disposition of affected parts. TE's EP-II specification excludes damaged contacts and housings from use and states that those parts cannot be repaired. That restriction belongs to the cited system; establish the corresponding rules for the offered product. TE EP-II specification, section 3.8.
Review changes to terminals, housing or lock variants, wire construction, inspection fixtures and rework methods. Keep routing support in the cable assembly strain-relief guide: terminal retention evidence does not approve unsupported cable loading.
For the separate electrical release package, use the harness test-report guide. Connect both packages to the same accepted assembly configuration.
Send a terminal-retention RFQ
Send the connector bill of materials, cavity drawing, inspection scope and quantity. Request proposed evidence, deviations and separate costs for any additional evaluation or documentation.
Buyer FAQ
Does a closed TPA prove every terminal is correct?
It supports only what the specified locking mechanism and inspection method demonstrate. Correct part identity, cavity assignment, terminal condition and required electrical results still need their own evidence.
Can a continuity pass replace retention inspection?
No. Electrical continuity and mechanical retention address different requirements. Specify the necessary checks and connect their records to the same assembly rather than treating one pass statement as universal acceptance.
Should every shipment receive a destructive pull test?
Do not assume that requirement. Agree the applicable method, sampling, acceptance criteria and specimen disposition. Distinguish routine assembly confirmation from a quantified evaluation that may affect the tested specimen.
What makes two inspection quotations comparable?
Use the same part combination, populated-cavity schedule, inspection coverage, required reports and rework rules. Ask each supplier to identify additional evaluation costs and proposed delivery conditions without assuming a standard price or lead time.