Bad alternator or battery??

Question

I drove my car to work this morning, and it worked just fine. After work, I got in the car and tried to start it and nothing happened. (NOTE: I UNLOCKED THE CAR WITH THE KEYLESS REMOTE) You could barely see any lights on the dash. I got the car jumped and I drove it home. Once home, I turned the car off and tried to start it again. Nothing. So, I took the battery to Auto Zone and the battery tested GOOD. The Auto Zone guy told me to test the alternator by taking of the positive battery cable while the car is running. If the car cuts off, then the alternator is bad. Well, I tried this and the car stayed on! My mom noticed before she jumped the battery that when she pressed down on the top of the battery where the water goes, the car would come on! We put water in the battery but still the car wouldn't start. After jumping yet again, I let it run for about twenty minutes, cut it off, and now it starts right back up. Could it be the alternator or a bad connection??

Answer 1

Prob. just a bad connection try tightening the bolts on top of the battery. or maybe use a wire brush and scrub the terminals.

Answer 2

Dear Miss Jessica If your battery keeps failing, there are reasons for this # 1 Defective in manufacturing # 2 Hitting potholes breaking inner connections that hold battery cells together to aquire a full 12 volts, each cell puts out 2 volts, X 6 make 12 volts. Testing the battery is mainly with a volt meter, you can do this one by yourself. It should read in a healthy battery 12.6 minimum. When the vehicle is running, the battery should read 13.8-14.0 If the reading is higher then this like 15.0, the charging circuit (the alternator) will eventually fry the battery from (over-charging) causeing a defective state. So, take the battery out, disconnecting the green or black battery cable first, take it to a station, ask to have it fully charged, costs about 10.00 & "load test the battery. Re-install the battery, if the battery is in the same condition, Either reason number 2 is at hand or the alternator burned the cells.

Answer 3

If you have a voltmeter, check the voltage across the battery with the engine off, then again after you start the engine. If the voltage is lower with the engine running, the alternator is bad.

Since it seems 'fixed' after you took the battery terminal off and then put it back on, I'm guessing a bad connection and removing and reinstalling the terminal removed enough crud to make a better connection.

If there are whitish deposits on the battery terminals, they are corroded and should be cleaned. Remove the cables (BTW, always remove the negative terminal first and reconnect it last), clean them with a wire brush (both the cables and the terminals on the battery), then coat them with petroleum jelly or automotive grease before putting them back on.

You should try pressing on the battery in different places to make sure that what your mom noticed wasn't a cracked plate or some other internal problem with the battery.

Answer 4

if you can start the car try turning on the lights or wipers in the car if the lights are dull try a bit of accelorating if the light become brighterits proberly the battery or may be you have a loose conection between the alternater and battery also check that thebelts are tight ,or you could have a faulty battery termanial one of the poles could have seperated between the top and bottom inside the battery p.s. the keyless remote has its own battery in the remote so it has nothing to do with starting the car

Answer 5

"My mom noticed before she jumped the battery that when she pressed down on the top of the battery where the water goes, the car would come on!"

Could you elaborate on this a bit?
Sounds like a possible cracked battery terminal inside the battery.... Or a bad cell,,, but I'm not sure I'm interpreting it correctly.

Answer 6

Clean the battery terminals sounds more like a bad connection. While your at it check the wire that goes to the starter sometimes that gets corroded and drops your amps thus no start

Answer 7

Sounds like a bad connection. It's not uncommon for a connection to break inside the battery. But it'll have to be replaced because you can't fix something like that.

Answer 8

clean the battery terminals on the battery and the battery cables real good and reinstall and make sure they are tight and try again tomorrow and see if the problem is fixed.

Answer 9

Bad starter solenoid or switch is a possibility.