Electrical

Electrical Services for Commercial Trucks & Trailers

Expert Diagnostics, Wiring Repair & Lighting Systems | STTR, Inc. – Pacific, WA

Electrical problems don’t just slow you down—they can take your entire rig off the road. At Sound Truck & Trailer Repair (STTR, Inc.), we offer full-service electrical diagnostics and repairs for semi trucks, heavy-duty and medium-duty trucks, and commercial trailers. Whether you’re chasing down a short, replacing key components, or upgrading your lighting system, our certified techs deliver fast, accurate, and DOT-compliant electrical solutions.


Complete Truck & Trailer Electrical Services

Our trained technicians work on OEM and aftermarket electrical systems for all makes and models of commercial trucks and trailers.

We service and repair:

  • Battery & Charging Systems

  • Alternators, Starters & Relays

  • Trailer Plug Wiring & Connectors (7-pin, 4-pin, etc.)

  • Power Distribution & Fuse Panels

  • Ground Faults & Shorts

  • Cab and Trailer Lighting Systems

  • ABS & EBS Wiring Diagnostics

  • Load and Liftgate Wiring

  • Switches, Sensors & Control Modules

  • Engine Harnesses and Terminals

  • Inverter & Auxiliary Power Systems

If it runs on a wire or sends a signal, we can inspect it, repair it, and make sure it’s working safely and efficiently.


💡 Lighting & Signal System Troubleshooting

Malfunctioning or non-compliant lights can lead to DOT violations, safety hazards, and downtime. STTR specializes in repairing and installing:

  • Headlights (low/high beam)

  • Marker lights & clearance lights

  • Brake, turn, and tail lights

  • Reverse/backup lights

  • Trailer ID lights

  • Reflectors & visibility systems

  • Interior trailer lighting

  • Beacon, strobe, and auxiliary lights

  • Aftermarket LED upgrades

We also test for voltage drop, signal loss, and broken connections in both truck and trailer lighting systems to restore full functionality.


🧰 Fleet Electrical Service & Preventive Checks

Avoid costly roadside surprises by incorporating electrical system checks into your fleet’s preventive maintenance program. We help identify issues like:

  • Corroded or damaged connectors

  • Failing batteries or alternators

  • Intermittent lighting issues

  • Improper voltage flow or ground loss

We can even trace electrical faults between tractor and trailer and repair them on-site to reduce downtime.


We provide Roadside Service 24 Hours a day, 7 Days a Week, all year long.

For scheduled services, at our shop in Pacific, WA: Monday–Friday, 8 AM to 5 PM

  • 898 Valentine Ave SE, Pacific, WA 98047

  • Open Monday through Friday, 8:00 AM – 5:00 PM

  • Serving the Puget Sound trucking and fleet community


Why Choose STTR for Electrical Repairs?

  • ✔ Commercial Truck & Trailer Electrical Experts

  • ✔ OEM & Aftermarket System Experience

  • ✔ Diagnostics & Clean Wiring Repairs

  • ✔ Quick Turnaround with Reliable Results

  • ✔ Trusted Since 2008 by Owner-Operators & Fleets


📞 Call (253) 691-6645 or visit www.STTRWA.com to request a diagnostic appointment today.
Power up your rig with STTR—where electrical problems meet their match.

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