Free Buyer Resource

Wire Harness Factory Requirements Checklist

The 60-point checklist buyers use to brief a wire harness factory and get accurate quotes — the exact specifications and documents to confirm with your supplier before you release an RFQ. Free printable PDF.

Download the PDF Checklist

Most quoting delays and field failures trace back to one thing — an incomplete brief. Use this wire harness factory requirements checklist to lock down every specification before you send a supplier your RFQ. The more of these customer requirements you define up front, the faster and more accurate your quote, and the fewer surprises in production.

Work through all nine categories below, or grab the printable PDF to share with your engineering and procurement team.

1. Drawings & Documentation

2D assembly drawing with overall and branch dimensions plus tolerances
Wire list / from-to schedule: every conductor's gauge, color, length, and both endpoints
Connector and pinout diagram for each connector position
BOM with exact manufacturer part numbers (avoid "or equivalent" unless pre-approved)
Revision number and date on every drawing and document
Approved-alternates list for long-lead or allocated components

2. Wire & Cable

Conductor gauge (AWG or mm²) for each circuit
Insulation type and temperature rating (PVC, XLPE, PTFE/ETFE, silicone)
Voltage rating per circuit
Shielding requirement: braid or foil, and required coverage %
Jacket material and color
Conductor stranding (fine-strand for flex / continuous-flex applications)

3. Connectors & Terminals

Connector manufacturer and exact part numbers: housing, terminals, and seals
Terminal plating (tin, gold, or silver) per application
Crimp specification and approved applicator / tooling
Gender, keying, and polarization for each connector
Cavity plugs / seals for unused positions on sealed connectors

4. Mechanical & Assembly

Overall length and each branch length, with tolerances
Breakout points and their dimensions
Protection: convoluted loom, conduit, braided sleeving, or tape — and coverage
Strain relief / overmold specification, including pull-force and minimum bend radius
Labeling and marking: wire markers, heat-shrink labels, and exact printed content
Mounting hardware: clips, cable ties, tie-mounts, P-clamps, and positions
Maximum bundle diameter or routing constraints

5. Electrical & Performance

Continuity / point-to-point map for 100% verification
Hipot (dielectric withstand) voltage and dwell time, if required
Insulation resistance threshold
Impedance and twist requirements for data or signal pairs
Maximum current per circuit

6. Testing & Quality

Is 100% continuity testing required?
Is hipot testing required, and to what spec?
Crimp pull-force testing and sampling plan
Target IPC/WHMA-A-620 class (Class 1, 2, or 3)
First Article Inspection (FAI / AS9102) required?
PPAP level required (automotive)?
Test reports and Certificate of Conformance with each shipment?

7. Compliance & Certifications

RoHS and REACH compliance
UL recognition and required style numbers
Industry QMS: IATF 16949 (automotive), ISO 13485 (medical), AS9100 (aerospace)
Region-specific marks (CE, etc.)
Material certificates and required level of lot traceability

8. Commercial & Logistics

Quantities: prototype count and estimated annual usage (EAU)
Minimum order quantity (MOQ) and price-break tiers
Lead time for prototype and for production
Tooling / NRE cost and ownership terms
Packaging: anti-tangle, ESD, individual bagging, or kitting requirements
Incoterms and shipping method
Payment terms

9. Communication & Sign-off

A single engineering point of contact (engineer-to-engineer)
Expected response-time / turnaround
Sample approval gate required before production release
Change control / ECN process
NDA signed before sharing drawings

Get the Printable PDF Checklist

Send it to your team and tick off every requirement before your next RFQ.

Frequently Asked Questions

What should I send a wire harness factory in an RFQ?

At minimum an assembly drawing, a wire list, a connector/pinout list, a BOM with manufacturer part numbers, quantities (prototype plus annual usage), the operating environment, and your test and certification requirements. This checklist covers all of it.

What is the difference between an RFQ and this checklist?

The RFQ is your request for a quote; the checklist is the set of specifications that make that RFQ complete. A complete checklist means an accurate quote with no back-and-forth.

How many prototypes should I request?

Three to five is typical — enough for fit checks, electrical testing, and a retained golden sample.

Do I need to specify an IPC/WHMA-A-620 class?

Yes. Class 1, 2, or 3 sets the acceptance criteria for the whole build. If you do not specify, you may get a lower class than your application needs.

Ready to Quote?

Send WellPCB your drawings and this completed checklist — our engineering team responds within 24 hours with a realistic timeline and a transparent quote.

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