1. Splice identity
Assign a unique reference that can be followed across the drawing, wire list, connection table, BOM, and inspection information.
Wire Harness Splice Documentation Requirements for OEM Drawings
CONTROL EVERY BRANCH CONNECTION
Wire Harness Splice Documentation Requirements for OEM Drawings
Define circuit relationships, splice identity, location, component requirements, protection, inspection inputs, and revision status before quotation or build review.
A splice symbol alone may not give engineering, purchasing, quality, and manufacturing teams enough information to interpret the same harness definition.
Quick answer
A quotation-ready splice definition should show which circuits join, how the splice is identified, where it belongs in the harness, which customer-approved component and protection requirements apply, what acceptance information controls review, and which document revision is current.
WHY SPLICE DATA MATTERS
Connect the electrical definition to the physical harness
A splice affects more than a wiring diagram. It creates a relationship among source circuits, destination circuits, wire identifiers, branch geometry, coverings, and inspection requirements. If those inputs sit in separate documents, the references should remain consistent.
For an OEM RFQ, the drawing should distinguish approved requirements from open decisions. The supplier should not have to infer circuit grouping, choose an unspecified material, or decide where a branch connection belongs.
This page focuses on the information package used to review a splice. It does not prescribe a universal splice construction, numeric limit, named material, or test method.
DOCUMENTATION PACKAGE
Eight inputs for a controlled splice definition
The exact document format can vary, but every affected reference should point to the same customer-approved requirement.
2. Circuit mapping
Show every wire or circuit entering and leaving the splice, using the same identifiers found in the approved connection definition.
3. Wire inputs
Connect each circuit to the customer-specified wire information without assuming an unapproved size, construction, color, or material.
4. Physical location
Define the relevant measurement references, branch relationship, routing zone, and any installation constraint that controls placement.
5. Construction input
Identify the customer-approved component or construction requirement and clearly mark any proposed alternative as pending review.
6. Protection input
State covering, insulation, sealing, strain-relief, or routing requirements where applicable without implying unverified performance.
7. Acceptance basis
Record the customer-approved inspection and electrical-test requirements that apply to the project, including any required records.
8. Revision status
Keep the splice definition aligned with the current drawing, BOM, connection data, change description, and approval record.
CROSS-DOCUMENT CONTROL
Use one reference across the full requirement set
Drawing
Show the splice reference, relevant location or branch relationship, orientation context, and notes that affect assembly.
Connection and wire data
List the complete circuit relationship and maintain consistent wire or circuit identifiers.
BOM and approvals
Identify approved component information, proposed alternatives, applicable protection, and current approval status.
RFQ REVIEW TABLE
Common ambiguity and the information that resolves it
| Review question | Information to provide | Risk if omitted |
|---|---|---|
| Which circuits join? | Complete input/output mapping with consistent circuit or wire identifiers | Different teams may interpret the electrical relationship differently |
| Where does the splice belong? | Controlled reference points, branch relationship, routing context, and applicable dimension definition | The electrical design may not align with the physical harness layout |
| What construction applies? | Customer-approved component or construction requirement and alternative-approval status | A proposal may be mistaken for an approved production input |
| What protection is required? | Project-defined covering, insulation, sealing, strain-relief, and environmental inputs where applicable | The requirement may be left to assumption |
| How is it accepted? | Applicable customer-approved inspection, electrical-test, and record requirements | Quotation and quality scope may be incomplete |
DRAWING WORKFLOW
Review splice changes before the next supplier action
Before quotation
Identify every splice and unresolved decision. Provide the current drawing, connection data, BOM, quantity context, and project-defined quality requirements.
Before prototype review
Confirm the approved circuit relationship, physical location, component inputs, protection, and applicable acceptance information.
After a design change
Update every affected reference rather than changing only the splice symbol or one line in the connection table.
Before production support
Release one aligned customer-approved definition and communicate the revision and effectivity for the applicable project.
Coordinate this information with the Wire Harness Drawing Checklist, BOM Requirements, Length and Dimension Requirements, and Revision Control Requirements.
CABLUM PROJECT REVIEW
Review splice inputs as part of the complete harness definition
Cablum is a Shenzhen-based custom wire harness and cable assembly manufacturer established in 2012.
Cablum can review customer drawings, specifications, BOM information, customer-approved requirements, and sample references where applicable. Custom wire harnesses and cable assemblies are manufactured based on the applicable customer definition.
Prototype and production support is available based on project requirements. Inspection and electrical testing are defined according to customer specifications and the applicable project scope.
For related support, visit Engineering & Prototyping, Quality Testing, Connector Selection Requirements, or the broader Products page.
BUYER QUESTIONS
Wire harness splice documentation FAQ
Show a unique splice reference, the connected circuits, relevant wire identifiers, the physical location or branch relationship, applicable construction and protection inputs, and links to the current BOM and connection definition.
The document structure may vary, but the drawing, connection data, wire list, BOM, and approval record should use consistent identifiers and point to the same customer-approved requirement.
The RFQ should identify approved requirements and open decisions. Any supplier proposal should remain visibly unapproved until the responsible customer contact completes the required technical and commercial review.
Include the customer-approved inspection and electrical-test requirements that apply to the project, along with any applicable acceptance basis and record requirement. Do not assume a universal method or coverage.
Cablum can review customer drawings, specifications, BOM information, customer-approved requirements, and sample references where applicable. Prototype, production, inspection, and electrical-test scope remain based on the confirmed project definition.
PREPARE ONE ALIGNED REQUIREMENT SET
Send your wire harness splice definition for project review
Share the current drawing, circuit mapping, BOM, splice references, dimensions, quantities, revision status, and project-defined inspection needs.