Top 7 Wiring Harness Manufacturers in California 2026
Last updated
FirmsLedger lists 7 wiring harness manufacturers headquartered in California. That is more than any other state; Pennsylvania is next with 6. They are spread across 7 cities, including Fremont, Fresno, Gardena and Hesperia.
By specialty, California has switchgear (23), electrical wire & cable (20), solar panels (19), transformers (7) and control panels (4) listings.
| Company | City | Specialty | Phone | Website |
|---|---|---|---|---|
| Mermar Electronics | Hesperia | PCB Assembly (SMT, Through-hole, Mixed Technology) | — | mermarinc.com |
| THACO INDUSTRIES USA LLC | Gardena | Stamping | (310) 418-9998 | thacoindustries.com |
| Valley Services Electronics | San Jose | PCBA Design Services | (408) 284-7700 | vse.com |
| Compass Made | Fremont | Electromechanical assembly | — | compassmade.com |
| Tech Electronic Systems INC | Upland | Engineering services | (909) 986-4395 | techelectronicsystems.com |
| Fresno Truck Parts & Machine Shop | Fresno | Corrosion-Resistant Protective Coating | (559) 746-9595 | fresnoparts.com |
| Motherson SAS Automotive | Newark | Modules & Polymer Products Division | (510) 326-2332 | motherson.com |
Mermar Electronics
Hesperia, California
Mermar Electronics is a contract electronics manufacturer based in Hesperia, California, founded in 1999. The company provides PCB fabrication, assembly, cable harness, box build, and electro-mechanical assembly services from a single facility in the High Desert region.
Valley Services Electronics
San Jose, California
Valley Services Electronics (VSE) operates from San Jose, California, with a second facility in Reno, Nevada. The company has been providing printed circuit board assembly and electronics manufacturing services for over forty years, though a specific founding year is not disclosed.
Fresno Truck Parts & Machine Shop
Fresno, California
Fresno Truck Parts & Machine Shop operates from Fresno, California, serving the Central Valley and surrounding regions with heavy-duty truck and trailer components. The company does not publish a founding year or ownership structure, and no founders are named in its public materials.
Frequently asked questions
Which certifications do wiring harness manufacturers in California list?
ISO 9001: Valley Services Electronics, Compass Made and Tech Electronic Systems. ISO 9001:2015: Mermar Electronics and THACO INDUSTRIES USA. ITAR Registered: Mermar Electronics and Valley Services Electronics.