Dead battery or alternator?


WHen I try to start my car, it makes a repetitive, fast clicking noise and doesn’t start.

Can you tell strictly from this info if it is the battery or alternator or or there other tests I can do? Already tried jumping the car (it will run after being jumped) but will not restart if I shut it off. There is also some blue material coming from the battery terminals.



You might first want to remove the battery terminals and clean both the posts and terminals. The blue stuff you see is corrosion on the terminals which may be causing a poor connection at the battery.



Several “deep discharges” (battery totally dead) will damage a battery, and it will not hold a charge (or much of a charge). So whatever the problem is, you will probably need a new battery also.

Have both the battery and the alternator tested after you clean up the terminals.


As the others have suggested, you may have a perfectly good battery and alternator. Your problems may be due entirely to the corrosion at the battery terminals. Get them cleaned; your problem may disappear entirely.


Most of the time this is just a battery that needs replacing.


Don’t try to use your car’s alternator to re-charge a dead or almost dead battery. Alternators are designed to maintain a charged battery, not to charge a dead or almost dead battery. Pull the battery out. Take it somewhere for a re-charge. If the re-charge doesn’t work, replace the battery. While “you’re there”, clean both ends of both battery cables. Install new battery. If the terminals are clean with a known charged battery, you might just save the alternator. If you choose to try to re-charge a battery using the alternator, guess what you’ll be changing out next? Yup. The alternator. There are automotive service places that will check out the battery and charging system for cheap or free. A good independent shop will do it, too. Just don’t let them sell you both a battery and alternator until they show you on the testing device just why you need to change both out. I’ll bet that cleaning the terminals and installing a new, fully-charged battery is what you need done. Don’t run that vehicle except to get it to a shop for testing. Once you’re at the shop, if it won’t start, hey, what the heck? Guess where you are? At the repair shop already! They can use a portable jump start pack to get the vehicle into their bay. In the future, please include year, make, model and mileage. In this case, you didn’t tell us much about the battery. How long has it been in the vehicle? Typically, you can expect about 5-6 years out of a modern battery, but a lot depends on the quality of the battery, type of vehicle,type of driving you do, etc.


what do you think about this problem. Have a 2001 Daewo Lanos. We replaced the battery because the car wouldn’t start. Once new battery installed, started right up. Put some oil in it because of losing some alittle. Grampa did that. Tonight, I was driving down the street and the car just stopped on me!!! Dead!!! Tried to jump it but no luck. It wanted to turn over but didn’t. I added more oil without knowing Grampa already did that. Did I mess it up somehow. Or could it be another problem ?? Can’t seem to win for nothing.!!! HELP


You now have two problems to deal with. One, check the oil and see how high it is, compared to the full line. If needed, drain some out. It should not have influenced your starting problem. A good thing to do is verify alternator output checked when you buy a new battery. That way you can confirm the alternator is doing its job. I assume that did not happen when you replaced the battery. So, recharge the battery, then go to a mechanic or a place like Advance Auto Parts, where they can check the alternator function on the car. Depending on those results, you may have your answer. Until you do that, you don’t know whether you have a new problem, or a continuance of the old problem, which may have involved the need for more than just a battery.

Two items I bought years ago, when I had to keep some older cars running, was a battery charger, and a volt meter. This allows me to trickle charge a battery overnight when needed, and if I get the car started, to check the alternator output at home. Total cost today is less than $60, and the money it saves over time is considerable.


he has his own post on this problem, under a different name, at


You do not need to pull the battery out of the car to charge it with an external low or moderate rate (ordinary) charger. I know of no valid reason to do that.