Top 10 Questions to Ask Your Wire Harness Manufacturer
Stop getting vague answers. These are the specific questions that separate reliable manufacturers from risky ones—with real examples of good and bad responses.
Every manufacturer claims they're "high quality" with "competitive pricing" and "fast delivery." These claims are meaningless. What matters is how they answer specific, detailed questions.
After 18 years in the wire harness industry and working with over 2,500 customers worldwide, we've learned exactly what separates reliable manufacturers from problematic ones. These 10 questions will help you find out before you place an order.
How to Use This Guide
- Ask these exact questions — vague questions get vague answers
- Compare to the "good answer" examples — these are real responses from reputable manufacturers
- Watch for red flags — certain responses should make you walk away
- Use the follow-up questions — dig deeper if initial answers are vague
"What certifications do you hold? Who issued them? When do they expire?"
Why This Matters
Certifications prove verified processes and third-party accountability. Expired or fake certificates are more common than you'd think.
Good Answer
"We hold ISO 9001:2015 and IATF 16949:2016, issued by NQA Certification Limited, valid until April 10, 2026. We can provide the complete audit report upon request."
— Our actual response
Red Flag Answers
- ✗"We have ISO certification."
- ✗"Yes, we're certified."
- ✗"I'll need to check and get back to you."
🔍 Follow-Up Question
Can you send me a copy of the certificate? Does it specifically cover wire harness manufacturing?
Red Flag
Inability to provide certificate copies or vague answers about issuing body
"What is your monthly production capacity? How many large projects can you handle simultaneously?"
Why This Matters
Knowing real capacity helps you understand if they can scale with your needs and whether you'll get adequate attention.
Good Answer
"Our monthly production capacity is approximately 500,000 wire harnesses. We can handle 10-20 large projects simultaneously without compromising quality or lead times."
— Our actual response
Red Flag Answers
- ✗"We have enough capacity for your order."
- ✗"Our capacity is flexible."
- ✗"It depends on the project."
🔍 Follow-Up Question
What's your current capacity utilization? Do you have seasonal peaks that might affect my orders?
Red Flag
No specific numbers, only vague assurances
"What is your lead time? Please break it down by material sourcing and production."
Why This Matters
'Quick turnaround' is meaningless. You need specific timelines to plan your production schedule.
Good Answer
"Materials typically arrive within 2 weeks. Production takes 2-3 weeks. For complex products like 47 wires with 12 connectors, if there are no material shortages, processing can be completed within 2 weeks."
— Our actual response
Red Flag Answers
- ✗"We offer fast delivery."
- ✗"Usually 2-4 weeks, depending on the order."
- ✗"We'll do our best to meet your deadline."
🔍 Follow-Up Question
What happens if materials are delayed? Do you have backup suppliers?
Red Flag
Can't separate material lead time from production time
"Is your testing laboratory certified? What tests do you perform on every harness?"
Why This Matters
'100% tested' means nothing if you don't know what tests they perform and whether the lab is accredited.
Good Answer
"Our laboratory has obtained CNAS and ISO/IEC 17025 certification with international mutual recognition. Standard tests include continuity, insulation resistance, hi-pot, and pull force testing. Full test reports are provided with every shipment."
— Our actual response
Red Flag Answers
- ✗"We test everything before shipping."
- ✗"Yes, we have testing equipment."
- ✗"We do 100% inspection."
🔍 Follow-Up Question
Can you provide a sample test report? What about environmental or specialized testing?
Red Flag
No lab certifications or inability to describe testing procedures
"Can we arrange a factory audit? How much notice do you need?"
Why This Matters
A manufacturer confident in their quality welcomes inspection. Long notice periods suggest they need time to 'prepare.'
Good Answer
"Yes, inspections can be arranged with 72 hours notice. You're welcome to bring your own quality engineers or third-party auditors."
— Our actual response
Red Flag Answers
- ✗"We need 2-3 weeks to prepare for a visit."
- ✗"We don't allow factory visits due to IP concerns."
- ✗"You can trust our quality without visiting."
🔍 Follow-Up Question
Can we bring a third-party quality engineer? Can we see production in progress?
Red Flag
Reluctance to allow visits or requiring extended notice periods
"Can you provide 3 customer references in my industry?"
Why This Matters
Industry experience reduces learning curves and costly mistakes. Real references prove actual capability.
Good Answer
"Certainly. We work with companies including Shenghe Electronic Technology, Zhonglang Qiteng Electronic Technology, and Jinfengsheng Electronics. We can arrange reference calls with customers in your specific industry."
— Our actual response
Red Flag Answers
- ✗"We have many satisfied customers."
- ✗"Our NDA agreements prevent us from sharing names."
- ✗"You can check our website for testimonials."
🔍 Follow-Up Question
Can you share case studies of similar complexity projects? Any projects in Australia specifically?
Red Flag
No specific references or using NDA as an excuse for all customers
"Do you provide engineering support? Is it included in the price?"
Why This Matters
Good DFM (Design for Manufacturing) support can save significant cost and time. Some manufacturers charge extra, others include it.
Good Answer
"Yes, we provide free engineering support with every project. Our engineering team of 50+ responds within 24 hours. This includes design review, DFM optimization, material recommendations, and 3D CAD drawings when needed."
— Our actual response
Red Flag Answers
- ✗"Just send us the drawings and we'll build it."
- ✗"Engineering support is available for a fee."
- ✗"We can provide basic support."
🔍 Follow-Up Question
If our design has issues, will you proactively point them out? Can you suggest cost-saving alternatives?
Red Flag
No engineering capability or extra charges for basic DFM review
"Can you break down your pricing? Are there any hidden costs I should know about?"
Why This Matters
The lowest quote often hides fees that appear later. Understanding cost structure helps you compare fairly.
Good Answer
"Our quote includes materials, labor, testing, and standard packaging. Tooling/fixture costs are listed separately if required. Orders over $1,000 AUD include free shipping to Australia. There are no hidden fees—everything is itemized."
— Our actual response
Red Flag Answers
- ✗"We'll confirm the final price after you place the order."
- ✗"Our prices are competitive."
- ✗"Tooling costs will be determined later."
🔍 Follow-Up Question
Do sample costs credit toward production orders? How are engineering changes priced?
Red Flag
Reluctance to provide itemized breakdown or 'TBD' items
"What happens if we receive defective products? What's your warranty policy?"
Why This Matters
Problems will occur eventually. How they handle issues matters more than promises of perfection.
Good Answer
"We offer free replacement or refund for any quality issues. A dedicated quality engineer will respond within 72 hours with a solution. We conduct root cause analysis and implement corrective actions to prevent recurrence. Our target defect rate is below 0.1%."
— Our actual response
Red Flag Answers
- ✗"Our products don't have quality issues."
- ✗"We'll handle it on a case-by-case basis."
- ✗"Quality issues are rare, so we don't have a formal policy."
🔍 Follow-Up Question
What was your customer complaint rate last year? Can you share an example of how you resolved a quality issue?
Red Flag
No formal warranty policy or claims of zero defects
"Do you have local support in Australia? Who will be my primary contact?"
Why This Matters
Time zone and language barriers impact communication efficiency. Local support means faster issue resolution.
Good Answer
"Yes, we have an office in Melbourne at 1/30 Seaford Road, Seaford VIC 3198. Local phone: +61-3-9785-1090. You'll be assigned a dedicated project manager who will be your single point of contact throughout the project."
— Our actual response
Red Flag Answers
- ✗"You can email us anytime."
- ✗"We have sales representatives who visit occasionally."
- ✗"Our team in China can respond during your daytime."
🔍 Follow-Up Question
Can I reach someone for urgent issues on weekends? Will I have the same contact person throughout the project?
Red Flag
No local presence or rotating contacts
Bonus Questions (If Time Allows)
- 11How do you handle engineering changes mid-production?
- 12Do you offer inventory management or VMI (Vendor Managed Inventory)?
- 13What's your employee turnover rate in production?
- 14What ERP/traceability system do you use?
- 15Can we establish a long-term supply agreement with fixed pricing?
Supplier Evaluation Checklist
Use this checklist when evaluating wire harness manufacturers. A strong supplier should check most of these boxes:
Certifications & Quality
- ISO 9001:2015 certified (verified, not expired)
- IATF 16949 (if automotive applications)
- CNAS/ISO 17025 certified laboratory
- Willing to share audit reports
- Accepts 72-hour notice audits
Capability & Experience
- Specific capacity numbers provided
- Experience in your industry
- Customer references available
- Clear lead time breakdown
- Engineering support included
Communication & Support
- Responds within 24-48 hours
- Dedicated contact person assigned
- Local office/support available
- Asks technical questions about your project
- Proactive in identifying potential issues
Pricing & Terms
- Itemized pricing breakdown provided
- Clear MOQ requirements
- All fees disclosed upfront
- Formal warranty policy
- Sample credit policy explained
How We Answer These Questions
Here's a summary of how OurPCB Australia answers each of the 10 questions:
| Question | Our Answer |
|---|---|
| Certifications | ISO 9001, IATF 16949 (NQA, valid to 2026) |
| Production Capacity | 500,000 harnesses/month, 10-20 large projects |
| Lead Time | Materials 2 weeks + Production 2-3 weeks |
| Testing Lab | CNAS + ISO 17025 certified, international recognition |
| Factory Audit | 72-hour notice, third-party welcome |
| References | Available across industries, 2,500+ global customers |
| Engineering Support | Free, 50+ engineers, 24hr response |
| Pricing | Itemized, no hidden fees, free shipping over $1000 AUD |
| Quality Issues | Free replacement, 72hr response, root cause analysis |
| Local Support | Melbourne office, +61-3-9785-1090 |
Ready to Ask Us These Questions?
We welcome detailed questions—it's how we know you're a serious buyer who values quality. Contact us today and put our answers to the test.
Call Melbourne
+61-3-9785-1090
Email Us
ar@ourpcb.com
Visit Us
1/30 Seaford Rd, VIC
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