When it comes to getting locked out of your car, prevention is simple and cheap.
Carry a spare key in your wallet or purse. Don’t keep it in a jacket pocket—jackets often are left in cars. And don’t try to hide it in a wheel well or beneath the floorboards. Give those thieves a little credit.
Get into the habit of locking your car door with the key. This ensures you have it with you when the car is locked up.
Write down the key code number and keep it in your wallet or purse. A locksmith may be able to make a new key using the number. The key code number sometimes can be found on a sticker in the glove box, sometimes in the car’s owner manual, sometimes on a metal tag accompanying the key, or you can ask the dealer.
4. Dead Battery
People had been running out of gas for over a decade and having flat tires for nearly as long when Cadillac introduced the electric starter in the 1912 model year. As the hand crank gradually was phased out, battery problems came on strong.
Modern batteries require little maintenance, but over time they eventually become too weak to start the car. They also can be adversely affected by extremes of cold and heat.
"Low maintenance" batteries occasionally may need to be topped off with distilled water, while "maintenance free" batteries have sealed covers instead of filler caps, so you couldn’t top one off if you wanted to. This doesn’t mean they’re truly maintenance free, however. You should check regularly for loose, dirty, or corroded terminals and cables. These can drain power or prevent the battery from charging. Use a commercial cleaner or a mixture of baking soda and water with a wire brush to clean corroded terminals.
Since batteries pack less of a punch with age, be aware of the length of your battery’s guarantee. Five years is a common figure. While the battery may last well beyond its guarantee, it quite possibly will not and, even if still alive, may not be able to perform as it did when young. Replacement as the battery’s expected age limit arrives can be a helpful bit of preventive maintenance.