Wire Harness Testing and First-Article Inspection Checklist
A wire harness should be inspected against its drawing and validated against a documented process. Checking only continuity can miss a weak crimp, an intermittent strand, a reversed cavity or an insulation defect.
Separate first-article approval from routine inspection
First-article inspection proves that the supplier has interpreted the drawing correctly and that the process is capable. Routine inspection verifies that production continues to meet the approved condition.
| Stage | Typical evidence | Release decision |
|---|---|---|
| Drawing and sample approval | Cavity map, wire list, terminal list, length datum and test plan | All open questions resolved |
| First article | Dimensions, continuity map, pull data, cross-section and electrical results | Approved condition locked |
| Routine production | Visual, electrical, dimensions and process checks at defined frequency | Shipment released |
Electrical test plan
- Verify every intended circuit from connector cavity to destination.
- Test for shorts between adjacent and unrelated circuits.
- Confirm connector, wire colour, label and branch length against the drawing.
- Measure insulation resistance when required by the application.
- Add high-potential testing only when the voltage and isolation requirements justify it.
Crimp and termination checks
Measure crimp height or width using the method specified for the terminal. Inspect conductor and insulation crimp proportions, strand damage, terminal deformation and contact seating. Cross-section samples should be captured at the frequency defined by the approved process.
Pull force should be checked against the limit for the approved terminal-and-wire combination. Do not move a value from one terminal family to another without evidence.
Mechanical and assembly records
- Overall and branch lengths from a defined datum
- Connector gender, keying and cavity numbering
- Seal, lock, terminal position assurance and strain-relief condition
- Label content, orientation and resistance to the expected environment
- First-article photos, approved sample identity and drawing revision
- Reaction plan for failed pull, continuity, dimension or cross-section results
Documentation package for OEM approval
Keep the approved drawing with revision history, bill of materials, terminal and wire datasheets, first-article report, test fixture map, process parameters, deviation approvals and packaging instructions together. The production record should identify the exact revision built.
Have a harness drawing ready for review?
Send the connector part numbers, cavity map, wire list, lengths, tests and annual quantity. We will flag missing requirements before sample or production quotation.
Continue with the wire-harness drawing checklist, crimp, solder and ultrasonic process comparison or the connector sourcing hub.
Frequently asked questions
What should a continuity test prove?
A continuity test should prove the intended end-to-end circuit and also detect shorts between adjacent or unrelated circuits. The test fixture and acceptance record should use the current drawing revision and cavity map.
When is a crimp cross-section required?
A cross-section is normally part of process qualification, first-article approval and periodic process verification. Its frequency should be based on the customer requirement, production volume and process stability.
What records should accompany the first article?
Keep the drawing revision, material and terminal approvals, dimensional results, continuity map, crimp or weld evidence, pull-force data, electrical results, photos where useful and all approved deviations.
