Send a controlled drawing, wire list, exact end connections, service conditions, required acceptance records and order quantities. Mark unresolved fields explicitly. This lets a supplier distinguish a budget estimate from a quotation against a released specification.
An RFQ organizes the purchasing evidence; it does not select a safe cable size, fuse rating or test voltage for an unknown circuit. Have the responsible designer establish those requirements. A catalog photograph, nominal voltage and a request for “the same cable” leave too many assumptions for a reliable comparison.
Assemble one revision-controlled inquiry package
Give the assembly a part number and drawing revision. Put the drawing, bill of materials, wire list, mating references and acceptance requirements in the same package. State which document controls if two requirements conflict, and identify who can approve deviations.
The checklist below intentionally contains fields rather than a ready-made electrical design. Replace each field with an approved requirement or mark it as open. Do not copy illustrative current, conductor and fuse values from an unrelated application.
On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.
| RFQ field | Information to supply | Ask the bidder to confirm |
|---|---|---|
| Application | Circuit function, installation location and duty | Assumptions and scope of any proposed engineering review |
| Electrical basis | Maximum relevant voltage, load profile and approved protection information | Offered construction and unresolved design inputs |
| Cable | Exact wire part or construction, conductor size, strand class, insulation and finished OD range | Manufacturer/part identity and any alternative proposed |
| Length | Endpoints, routed or straight condition, branch datums and tolerances | Measurement method against the drawing |
| End A / End B | Housing, contact, seal, lock, boot, mating part and orientation | Complete component list rather than housing identity alone |
| Environment | Temperature, movement, fluids, moisture, abrasion and installation limits as applicable | Supported conditions and exclusions |
| Verification | Acceptance-plan revision, required coverage and record format | Existing evidence versus tests included in the offer |
| Quantity and packing | Samples, production tiers, unit definition, labels and traceability | Order unit, packing increments and variant identification |
| Commercial scope | Required shipment basis and separately requested services | Unit price, tooling, sample/testing charges, lead-time assumptions and validity |
When an input is unknown, ask for the information needed to resolve it and keep the quotation conditional. An unanswered field should not silently become a supplier-selected design requirement.
Specify cable and connector compatibility together
Conductor size and finished insulation diameter are separate dimensions. Identify both, together with conductor construction and the exact terminal/contact. Ask for the connector manufacturer's applicable drawings and assembly instructions for that combination.
For example, Molex's PowerWize 3.4 mm application specification separately identifies wire gauges, an insulation-diameter limit, contact part numbers and corresponding tooling. This illustrates the evidence to request; its dimensions and processing settings are not instructions for a different connector or a battery lug. Molex application specification, sections 3 and 5.
List housings, contacts, seals, secondary locks, cavity plugs and protective parts where applicable. Specify whether each end is populated and include the mating part reference. A family name or housing color does not settle contact size, keying or the complete bill of materials.
For an assembly with several circuits, supply connector names and cavity numbers with the viewing direction. Distinguish mating-face and wire-entry views. Link those identities to a pin-to-pin wire list; photographs are useful context but do not replace a controlled mapping. Use the pinout and cavity-view guide for the detailed handover.
Define what the length measurement includes
Choose endpoints that a supplier and inspector can reproduce: terminal-hole centers, connector reference faces or specified overall ends. State whether a dimension is measured along the routed assembly, in a straightened condition or in a fixture. Add terminal clocking, branch-breakout positions and service-loop requirements where they affect fit.
Here is a hypothetical document mismatch, not a manufactured sample result. The buyer requests 600 mm between ring-hole centers. One bidder replies “600 mm overall,” while another confirms the specified centers. Both replies contain the same number, but only the second uses the stated datum. Do not decide from price until the first bidder confirms a corrected drawing or an explicitly approved deviation. The example does not propose a production tolerance.
For assemblies with bends or branches, use the length, datums and breakout guide. Do not assume conductor cut length equals finished assembly length.
Define acceptance evidence before requesting a sample
Ask which documents describe the proposed wire–contact–tooling combination and which checks will be performed on your samples. Identify the test provider, sample quantities consumed by destructive checks and the report format. A supplier's equipment list is not evidence that a particular construction has passed.
For electrical testing, identify required paths and isolation boundaries, not just a checkbox reading “100% tested.” Distinguish continuity, insulation resistance and dielectric withstand where the acceptance plan requires them. Harnesses with embedded components need an appropriate test program: Cirris explains how grouping and program verification matter for assemblies containing components. Its tester-specific method is not a universal instruction to apply a high voltage to every completed harness. Cirris component-aware testing guidance.
Agree the approved conditions and coverage with the responsible engineer. Ask for drawing/program revisions, unit or lot identities, results, exclusions and retest dispositions. See the cable harness test-report guide for the difference between a pass label and a reviewable record.
At this stage, request a scope-based cable quotation with the evidence requirements attached. Ask suppliers to separate existing records from work that still needs to be quoted and performed.
Normalize offers before comparing the unit price
Use a response column for every RFQ field: confirmed, deviation, excluded or open. Then reconcile three kinds of cost without assuming a supplier's MOQ or delivery promise:
- Delivered assembly: check the complete bill of materials, purchase unit, packing and shipment basis.
- One-time work: identify tooling, fixtures, samples, qualification or documentation charges separately.
- Recurring evidence: identify agreed production checks, traceability and reporting included with each order.
A hypothetical supplier may include the housing but exclude contacts, seals and testing. Another may quote the complete assembly against the same drawing. The lower headline amount is not an equivalent delivered scope. Ask for the missing items and revised commercial terms before choosing; neither offer is described here as technically approved.
Keep every accepted deviation in the released package. When a wire source, terminal, process or drawing changes, use the first-article and change-control guide to decide what must be reviewed again. Preserve the approved sample's identity rather than relying on an email saying “same as last time.”
Buyer FAQ
Can I request a quote before I have a finished drawing?
Yes, for a clearly conditional estimate. Supply the application, mating references and known constraints, mark open questions, and ask what is needed for a firm quotation. Do not treat an estimate against assumptions as approval to manufacture.
Is a photo enough to identify the connector?
Usually it is only supporting information. Request exact housing, contact and mating part references, keying, cavity mapping and drawings. If identity is uncertain, resolve it through an agreed sample or identification review before approving substitution.
Can a supplier choose the wire size from the current figure alone?
The current figure alone does not describe the installation. Provide the designer's requirements, load profile, routing, environmental conditions and applicable constraints. Identify any sizing review as a separate responsibility with explicit inputs and approval.
Does 100% tested mean every requirement was checked?
No. It may describe the number of units tested without defining circuit coverage or test type. Ask which units, paths, boundaries, conditions and program revision the statement covers.
How should I request MOQ and lead time?
Tie both to the construction, quantity, packing and evidence scope in the RFQ. Ask suppliers to state sample timing, tooling dependencies, production timing and assumptions separately. This checklist does not establish SINAWATTS commercial terms.
Send the package for a project quotation
Review OEM/ODM cable assembly support, then send a cable assembly RFQ with the controlled package and open-point list. Request written confirmation of the offered construction, deviations and available evidence before releasing samples or production.