Work vans and upfitted trucks come with wiring the factory never installed — lightbars, inverters, ladder racks, lift gates, radios. When an electrical fault appears on one of these vehicles, the aftermarket circuits are the first place worth looking.
What Diagnostics & Check Engine Covers
- OBD-II and manufacturer-level scan tools
- Drivability and intermittent fault diagnosis
- Electrical, sensor, and emissions troubleshooting
- Detailed report of findings and recommended repairs
- EV diagnostics including Rivian
Added equipment is usually spliced into existing circuits, and a splice that's chafed, corroded or drawing more than the circuit was designed for causes faults that look like factory failures. Parasitic draw from an accessory that never fully powers down is the classic one: the truck starts fine all week and is dead on Monday morning. That's a measurable fault, not a mystery, and tracing it properly beats replacing batteries.
Load-related faults matter too. Trucks that tow or carry weight can log transmission-temperature and driveline codes that reflect what's being asked of them rather than a broken component — worth reading correctly before starting a big repair.
Boston Fleet Services traces this kind of thing on commercial vehicles every day. Call for current pricing.
Tewksbury Questions About Diagnostics & Check Engine
- My work van's battery keeps dying over the weekend — what is that?
- Usually a parasitic draw from added equipment that doesn't fully power down. It's measurable: we test current draw with the vehicle asleep and isolate which circuit is responsible.
- Can aftermarket wiring cause check engine or electrical faults?
- Yes. Splices into factory circuits can chafe, corrode or overload, producing faults that look like factory component failures. Tracing the added wiring is part of diagnosing an upfitted vehicle.
- How far is Wilmington from Tewksbury?
- About 12 minutes to 779 Woburn St, our only shop.