Ask people what breaks on a car and you'll hear engine, transmission, maybe brakes. Nobody says wiring. But across 1.3 million owner complaints filed with NHTSA, the single most-reported category is the electrical system.
What owners actually complain about
Electrical faults account for 202,823 complaints — 15.4% of everything reported. More than the engine. More than the brakes.
| Component | Complaints | Share |
|---|---|---|
| Electrical system | 202,823 | 15.4% |
| Power train | 174,748 | 13.2% |
| Engine | 156,997 | 11.9% |
| Service brakes | 150,571 | 11.4% |
| Air bags | 148,198 | 11.2% |
| Steering | 103,430 | 7.8% |
The top three add up to more than 40% of everything owners bother to report. And the ordering is stable enough that it says something structural about modern cars rather than about any one model.
Why wiring beats engines
Because there's so much more of it than there used to be. A car built in 1995 had a fraction of the modules, sensors and control units that a 2020 model carries. Every screen, camera, sensor and assist feature is another thing that can fail — and unlike a worn engine, an electrical fault shows up as something visible and infuriating: a dead screen, a phantom warning, a door that won't lock.
There's also a reporting bias worth naming. An engine problem sends you to a mechanic; an electrical gremlin sends you to the internet. The complaint database captures annoyance as readily as it captures danger.
That said, air bags at 11.2% is not an annoyance category. That one is worth taking seriously on any used car, and it's exactly the sort of thing that generates open recalls you can check by VIN.
What I'd do when shopping
On a test drive, most people listen to the engine. Spend the time on the electronics instead: work every window, every lock, the infotainment, the cameras, the climate controls. The mechanical side of a well-maintained modern car is usually the reliable part.
And before you go, look up the model's complaint pattern — our reliability data by model shows which components generate the reports for that specific vehicle, which is far more useful than a general reliability score.
Frequently asked questions
What is the most common car problem reported by owners?
Electrical system faults, at 202,823 complaints or 15.4% of all NHTSA reports in our data — ahead of powertrain, engine and brakes.
Why are electrical problems so common now?
Modern cars carry far more modules, sensors and screens than older ones, and each is a potential failure point. Electrical faults are also highly visible, so owners report them readily.
What should I check on a used car test drive?
Work every electrical function — windows, locks, infotainment, cameras, climate. On a well-maintained modern car the mechanical side is usually the more dependable part.
Denis Kataev is a serial solopreneur and the founder of ForCar. With 15+ years in software engineering and 10 years in SEO, he builds data-driven products end to end — backed by a sharp eye for design. At ForCar he mines proprietary vehicle datasets, turning raw numbers into buying advice you can actually trust.
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