What people keep running into with automotive electrical
Complaints tagged automotive electrical, each raised by more than one person. One-off posts are not included.
17 recurring problems · 289 people · 4 forums we read
Raised more than once
Most people first.
- 168Vehicle cranks after fuel pump replacement but won't startA replacement fuel pump can deliver pressure while flooding the engine with excess gas, preventing it from catching. This leaves the vehicle cranking normally but refusing to start or run.
- 24Why does the check engine light come back on after replacing a sensor?When a persistent check engine light returns shortly after a sensor repair, it usually means the underlying fault—such as a failing catalytic converter or timing issue—was not fully resolved by replacing the component alone. This leaves drivers anxious about whether their car is safe to drive and unsure what to check next.
- 21How to handle random car error codes and weird driving feelingsCar error codes often pop up alongside intermittent physical symptoms like strange noises or jolting, forcing drivers to guess whether a part just needs cleaning or if an old repair failed. This ambiguity leaves people stuck trying to diagnose issues themselves by checking fluids and sensors, or debating whether to return to a mechanic for unresolved problems.
- 17Dashboard warning lights stay on but OBD2 scanner shows no errorsCar diagnostic scanners often fail to show fault codes for dashboard warning lights if the scanner only checks the basic engine module rather than specialized ABS or power steering systems. This leaves drivers unable to clear persistent lights like EPS or ESP, even when trying basic resets like disconnecting the battery. To locate the hidden fault, you need an advanced OBD2 tool capable of reading specific system codes beyond standard OBD2 engine trouble codes.
- 12Car still has electrical problems and high voltage after replacing partsPersistent vehicle electrical faults like high voltage spikes and limp mode often continue even after replacing major components like the alternator, battery, and ELD. This leaves drivers completely stuck after trying everything, unable to reliably diagnose the root cause of the ongoing system failure.
- 8Is my car battery dead or is it the alternator?When a car battery repeatedly dies after a couple of days and requires a jump-start, it is hard to tell whether the battery itself is failing or if there is an electrical problem with the alternator. This uncertainty leaves non-car people stranded and unable to reliably start or move their vehicles.
- 7New car battery installed but vehicle still has zero powerA brand-new battery will fail to restore power if the main ground strap between the engine block and the frame is severely corroded, or if rodents have chewed through a vital wiring harness. These hidden connection breaks leave the fuse box completely unpowered, preventing the vehicle from turning on at all.
- 6Why do car turn signals only work sometimes?Intermittent turn signal failure is typically caused by a loose wiring harness, a failing multi-function switch in the steering column, or a faulty gear selector position switch if signals only function while parked. These electrical glitches leave drivers without working blinkers or hazard lights while on the road, creating an unpredictable and hazardous driving condition.
- 6Headlights turning completely off when switching beamsSwitching between high and low beams can cause the headlights to shut off completely or stop working altogether, requiring drivers to repeatedly flip the switch or hit the dashboard to get them back on. This dangerous failure leaves drivers temporarily blinded in the dark and unable to rely on their main lighting while driving.
- 5Should I replace just the alternator pulley or the whole alternator?Replacing just the pulley is cheaper, but on a high-mileage vehicle near 200k miles, a new alternator is often the more reliable choice. Finding the most cost-effective option can be difficult when trying to balance DIY repair costs against long-term reliability.
- 3Why do multiple electrical accessories fail when starting the car?Multiple electrical accessories and systems fail simultaneously upon startup because a single component, such as a faulty ignition switch, a failing main relay, or a major grounding issue, is interrupting power to several circuits at once. This prevents essential features like power steering, air conditioning, and auxiliary devices from operating normally when the engine turns on.
- 3Why does my outside AC unit keep running when turned off?When an outdoor unit continues running despite being turned off at the thermostat, a failed or stuck contactor is usually to blame. Because power remains bridged, the only way to stop the system is by manually flipping the exterior switch or breaker.
- 2Dashboard lights still on after cleaning battery corrosionCleaning battery corrosion can leave drivers unsure if it is safe to drive and recharge the battery, fearing a potential alternator problem will drain the remaining power. This leaves them questioning whether a negative terminal issue is still affecting the car's electrical power while all the dashboard lights remain on.
- 2Can I splice wires to fix broken car lights with electrical issues?When multiple exterior lights like headlights, taillights, and license plate lights fail simultaneously alongside underlying electrical problems, drivers are left trying to figure out whether to splice wires together or deal with a dealer warranty. This leaves them stuck with non-working lights and unsafe vehicles while trying to work around complex electrical failures.
- 2Why did I get shocked reconnecting my car battery?Attaching the negative terminal can deliver an unexpected shock, despite common advice that changing a battery is completely safe. Additionally, making this connection often causes the car's alarm system to trigger instantly.
- 2Jeep stuck in park won't turn offVehicles falsely detect that they are not in park even when the shifter is physically in position, locking the shifter and refusing to let the ignition turn off. This traps drivers with electronics stuck on and drains the battery while they try to find a workaround.
- 2Dashboard lights and ABS lights flashing when using turn signalActivating the turn signal can cause unrelated dashboard lights, center console indicators, and even ABS or traction control lights to flash or turn on unexpectedly. This electrical glitch often points to a shared ground failure or a wiring short circuit in the steering column or tail light assembly.
Comes up alongside
Topics that keep appearing on the same problems — not topics with similar names.