DO NOTHING AT ALL WHEN YOU TURN THE KEY TO “START” Do all the lights on the instrument panel come on when you turn the key “on” ie: brake, Check engine, maybe oil light (on some models), ABS, battery/alt, If it’s an automatic Is it completely in PARK? Try starting it in Neutral if it starts then likely the transmission range selector is out of adjustment or the Neutral safety switch is bad or out of adjustment. These things need professional diagnostics.
JUST “CLICK” WHEN YOU TURN THE KEY TO START?
Possibly weak battery and or corroded cables, clamps, inspect/clean and have the battery professionally tested for AMPS NOT JUST VOLTAGE! With no Amps there is not enough power to turn the starter. Charge or replace battery. Still same now is the time to have the cables to the starter from the battery inspected and repaired cleaned of corrosion if ok have a qualified professional test the starter. But First verify the ENGINE IS ABLE TO SPIN AT ALL it could be “frozen” locked up due to a mechanical issue or, because of a week battery that turned the starter too slowly the bendix in the starter drive could be stuck in the engine flywheel and needs to be released. Try to turn the engine by hand with a wrench back and forth to verify the engine is “free”.
ENGINE TURNS OVER BUT WILL NOT START AND RUN?
Here is where experience in diagnostics comes into play. I see so many people try to be technicians and change parts hoping to “get it to start” It Kills me!! I specialize in NO-Start Diagnostics and it is a skill that many “mechanics” do NOT possess. Diagnostics is a systematic process that narrows down exactly the system(s) that are keeping the engine from starting. YouTube videos, your neighbor down the street, that guy at the parts store very likely have no help for you in this situation. Bring your vehicle to me or any fully qualified equipped diagnostics facility and have it checked. (Here is where I would NOT in nearly any case have a mobile “mechanic” attempt to diagnose your car! )I’ve seen first hand a customer that came to me with an intermittent NO CRANK NO Start condition. She had a mobile guy at her house she told me he “said” he needed to change the starter, She never actually seen him do it and of course it still didn’t start. She brought me the car and I troubleshot it, it was the body control module Never was the starter!! The customer bought the new module at the dealer and I installed it, She has never had another issue with no starting since. Sadly she paid the “mobile mechanic +$250! And her car still didn’t start. As you see I’ve avoided listing any possible tests as there are so many and where your start diagnostics and how you do it is critical. Do not try diagnostics on your own you will cost yourself $$$$ and aggravation and still will eventually end up paying a qualified technician to fix your car.