Battery or Alternator trouble with my car? What is wrong?

Question

About 3 months ago my car started having trouble where it would only start sometimes. I found out one of the connections on the battery terminal was loose so tried to fix it. However, it kept on happening and eventually progressed to the point where the car would just shut off while driving. I brought it to my mechanic who looked at the battery and alternator and said the alternator was fine but the battery was done. He put in a used battery and that worked fine till about two weeks ago. Now my car has trouble starting sometimes (it takes a few seconds you can hear it trying to start) and sometimes doesnt at all. Using anything once the engine is off and the key is in accessory position will make it so the next time i try to start it it won't at all (like the battery is getting drained very easily). So I need to bring my car back in soon and I am wondering from anyone with a lot of car knowledge what they think the problem is. Thanks for any responses, sorry for the long post.

Thanks for the replys so far. I have a 94 Camry LE with 140,000 miles and as far as I know its the original alternator.

Answer 1

First, make sure that the connections are secure, that they are making full contact, and that they are clear of any residue. If you still experience the problem, chances are, it's your alternator.

The alternator might still be working, but it's not working to full capacity. That causes your alternator to drain your battery. (the alternator is what normally generates electricity in your car when the car is running, the battery is actually the back-up for when the car is off and for turning it on).

Replace your alternator. In my opinion, it has a few months worth of unsteady battery-draining life left. Even if you bought a brand new battery, it would end up draining it.

Good luck.

Answer 2

It would be easier if we knew the year, make, and model of your car, but I'll give it a try. You said it got to the point where it would shut off while driving. This points to a bad connection in the electrical system, either at the battery or somewhere else, or a problem in the ignition system (creates spark for the spark plugs). If your alternator is charging but only minimally, a new or used battery in good shape can still be eventually drained. I might have the alternator checked again, perhaps by a different mechanic. Also, have the battery and the battery cables looked at.

If your car has electronic ignition (meaning it has computer-controlled spark timing as opposed to the mechanically driven cap-and-rotor type), then you could have a bad coil or ignition module (this controls the coils that generate the electricity that makes the spark plugs spark). Bad coils or ignition modules can cause hard starting, hesitation, and stalling if they burn out.

You ought to to add more information about your car so you can get more helpful answers specific to your year, make, and model. Click on the pencil icon below your posting and click on "Add Detail" and you'll be closer to the answers you're looking for!

Answer 3

You can do what goodanswer said, but I will expound on his suggestion, as it appears your funds are limited, like everyone else's.

Loosen the nut on the negative battery cable. Start the car and turn on the headlights and heater fan to high. Remove the negative terminal. If it still runs, the alternator should be good and the battery is at fault. If it shuts down, the alternator is bad.Turn it off and reconnect.

If the alternator is good;
I see he sold you a used battery. This is not a good idea. You really don't want to get stuck in a place you don't want to be at night with a dead battery. I'm not sure where you live, but batteries can be found on sale for less than $40. That's pretty good insurance, since you don't want to start hearing dueling banjos at night when your car won't start.

Answer 4

ok u dident say what type of car but first off with todays conputer systems dont mess with it unless u know how bring it to someone who does sounds like a dioide in the alt is backfeeding so it will drain u bat but u or ur man can test it for backfeed also u sayed he sold u a used battery maybe it was almost done have him retest the battery as well

Answer 5

Sounds like there is a constant drain on the battery from somewhere while the car is off, like a grounded wire.

Answer 6

Try this Start the car then remove the + cable from the batt. with engine running, if engine dies then alternator is causing short and running batt. down. Recommend replacing both if funds are available.

Answer 7

try to check your starter...