Alternator & Starter in Hutto, TX.

A charging-system test takes about five minutes and gives a definitive answer. A healthy alternator should produce 13.8–14.7 volts at idle with a moderate electrical load, and a healthy 12V battery should rest at about 12.6 volts after sitting. We also run a load test on the battery itself and check for AC ripple from the alternator, which catches a failing diode pack before it leaves you stranded.

On most cars and light trucks, alternator replacement takes 1–2 hours of labor. Some engines — particularly transverse V6s, certain Audi and Subaru layouts, and trucks with accessories stacked over the alternator — require removing intake components, motor mounts, or even the front cover, which pushes the job to 3–4 hours. We confirm the labor time from the service manual before quoting so there are no surprises at pickup.

Once the alternator stops charging, the car is running entirely off the battery, which typically lasts only 20–45 minutes before voltage drops too low to fire the ignition coils and fuel injectors. Headlights, power steering assist, and ABS can cut out without warning before the engine stalls, which is dangerous in traffic. We strongly recommend a tow rather than trying to drive in — it's cheaper than a collision and far safer.