Plain-English car diagnostics and troubleshooting: what your warning lights mean, how to test the battery and charging system, and how to track down running problems like misfires and vacuum leaks. Each guide is written for owners doing their own checks, with clear steps and no jargon.
Warning lights
- What does the check engine light mean? — causes, whether it is safe to drive, and typical repair costs.
- Check engine light: flashing vs steady — the one distinction that decides whether you keep driving.
Starting & charging
- How to test a car battery — state of charge, cranking, and when to replace it.
- Bad alternator symptoms (and how to test) — confirm a charging fault before you spend money.
- Car cranks but won’t start — work through spark, fuel, and compression.
- Car won’t start: full diagnosis — the complete no-crank and no-start tree.
Running problems
- Engine misfire & rough idle — the four causes and how to narrow them down.
- Find a misfiring cylinder without a scanner — the cylinder-drop and coil-swap method.
- How to find a vacuum leak — listen, spray, and smoke methods, confirmed with fuel trims.
Where to plug in
- Where is the OBD-II port? — find the diagnostic socket to read fault codes.