Precision Wire Harness Manufacturing & Contract Assembly
From prototype to production — wire harnesses, overmolding, control panels, and assemblies built in Middleville, Michigan.
What We Build
Comprehensive contract manufacturing capabilities under one roof.
Wire Harness Manufacturing
Custom wire harnesses engineered and built to your exact specifications. From single prototypes to high-volume production runs.
Learn More 02Overmolding
Durable, sealed overmolded connectors and assemblies for harsh environments. Custom tooling and material selection.
Learn More 03Control Panel Assembly
Complete control panel builds including wiring, component mounting, labeling, and testing.
Learn More 04General Assembly
Box builds, sub-assemblies, kitting, and turnkey assembly services. We handle production so you can focus on your product.
Learn More 05Prototyping
Rapid prototype builds to validate your design before committing to production. Fast turnaround and engineering feedback included.
Learn More 063D Printing
Additive manufacturing for fixtures, jigs, enclosures, and test blocks. Supports your wire harness and assembly projects.
Learn MoreWhy Manufacturers Choose H&L
Vertically Integrated
Wire harness, overmolding, panel assembly, and 3D printing under one roof. One vendor, zero handoff delays.
American Made
Manufactured in Middleville, Michigan. Shorter lead times, no offshore communication barriers, full IP protection.
Prototype to Production
Start with a single prototype and scale to thousands without switching vendors. We grow with your program.
Quality Obsessed
Every harness is tested. Every assembly is inspected. Professional workmanship standards guide everything we build.
Industries We Serve
Frequently Asked Questions
Common questions about H&L Manufacturing and our capabilities.
01What does H&L Manufacturing do?
H&L Manufacturing is a full-service contract manufacturer specializing in wire harness assembly, overmolding, control panel builds, general assembly, and prototyping — all from our facility in Middleville, Michigan.
02Where is H&L located?
We're located at 900 E Main St, Middleville, MI 49333. Our 54,000+ square foot facility houses all of our manufacturing capabilities under one roof.
03How long has H&L been in business?
H&L has been serving manufacturers for over 59 years, building a reputation for quality, reliability, and on-time delivery since day one.
04What industries do you serve?
We serve automotive, consumer & commercial products, RV & recreational, utility trailers & vehicles, industrial controls & automation, and agriculture & heavy equipment industries.
05Can you handle both prototypes and production runs?
Absolutely. We support everything from single prototype builds to high-volume production runs — and you never need to switch vendors as your program scales.
06What quality standards does H&L follow?
We follow IPC/WHMA-A-620 workmanship standards. Every wire harness is electrically tested and every assembly is inspected before it ships.
07Do you offer overmolding services?
Yes. We provide custom overmolding for connectors and assemblies, ideal for harsh environments requiring sealed, durable connections. We handle tooling design and material selection.
08What is your typical lead time?
Lead times vary by project complexity and volume. Prototypes can often be turned around in days, while production orders are scheduled based on your delivery requirements. Contact us for a specific timeline.
09How do I request a quote?
Simply visit our Request a Quote page and upload your drawings, specs, or BOM. Our team will review your project and respond with a competitive quote.
10Are you hiring?
Yes! We're actively hiring for 1st shift production positions. We offer a clean facility, great culture, and room to grow. Visit our Careers page to see open positions.
Join Our Team
We're hiring for 1st shift production positions. Clean facility, great culture, room to grow.
Ready to Discuss Your Next Project?
Send us your drawings and specs — we'll get back to you with a competitive quote.