Your car's electrical system runs because of several essentialcomponents including: a battery, fuses, and an alternator. Whenany one of these components fail, your car won't run or it willperform poorly. Unfortunately, it isn't always apparent whichpart is giving you the trouble. We'll examine each component,discuss its unique characteristics, and outline simplemaintenance options to help you make the proper diagnosis.

1. Alternators. Caralternator problems are usually noticed when you realizethe juice to your headlights has been reduced. No longer can yousee hundreds of feet in front of you, instead the light barelymakes it past the front bumper. Check the wires leading to thealternator and make sure that they are secure and free ofcorrosion. Examine your alternator belt for cracks as well asfor tension. If your headlights are still dim, then it is likelyyour alternator will have to be replaced. Don't put it off asthe alternator can drain your battery.

2. Batteries. If your car won't start, your battery maybe to blame. Most cars come equipped with sealed, maintenancefree batteries. Still, "maintenance free" isn't an entirelycorrect designation as corrosion can build up on the terminalscausing an otherwise fine working battery to fail. Remove thecables, clean with a wire brush, and reattach the cables. Applylubricant to each terminal to limit future corrosion. If yourcar's battery is not "maintenance free" add distilled water toeach cell as needed. Use a good set of jumper cables to get yourcar started. If the car still won't start the battery is eithercompletely shot or the starter or solenoid [relay] are notworking. Battery life varies depending on what type of batteryis in your car and usage; consider replacing your battery every3-5 years before problems arise.

3. Fuses. Your dash lights may be working, while yourleft rear blinker has failed. If that is the case, it is likelyyour electrical problems are with the fuses. You can pull offthe fuse panel [usually located under the dashboard] and checkto see which fuse has burned out. Today's cars use transparentblade style fuses that are rectangular in shape. Observe eachfuse and see if the internal wire has burned out. You can findthe fuse fast if the auto manufacturer has labeled each one bycircuit. If not, you will have to determine by a process ofelimination which fuse has failed and replace it.

Batteries and fuses are widely available at auto supply storesand most will carry a selection of alternators too. If you findprices for your Fordalternator or BMWalternator are too high, you can save plenty of money onoriginal equipment manufactured parts with some of the reputableonline providers. Shop with those retailers who have the widestselection of inventory, the best prices, and the most favorableshipping and return policies.