Crappy Battery or Alternator?

Question

My 95 eclipse won't hold a charge. It use to run fine for a few days after getting jumped. It died. So today. I got it jumped by my dad. And it wouldn't hold a charge at all. As soon as we took it off it'd die. Or 5 minutes later, it'd die. I've taken it to Autozone. Battery alone and they said battery was good. They recharged it. When I brought my car out, they said alternator was fine, battery sucked. Then I took it to a mechanic who said it as my alternator. The coolant lights and brake lights come on and when i rev, they shut off. I don't want to spend $150 to get the alternator replaced when its the battery. Thanks

battery says Aug. 06

Answer 1

I own something that may or may not be a shop and I think you need to stop getting jumped by your dad. Yeah it's a free country, but lets get real.

Answer 2

I had the same problem two days ago!! Luckily I know a good mechanic that can quickly help me in these situations. I would jump start the car and after 2-5 minutes the car would turn off, if I would take off the car would turn off a lot faster, in just seconds even.

So I called my friend who said that the car should stay on even without the battery once it is started. So I loosened one end of the battery, it doesn't matter if it's + or -, I jump started the car then removed one end of the battery and it instantly turned off. So the problem was the alternator, not the battery. The car was using up all the energy from the battery and the alternator wasn't repleneshing it... I got the new alternator at Auto Zone for 100 bucks and just paid 40 for the mechanic. But I have an 86 BMW 325, I don't know how much you would have to spend.

Answer 3

I will try and explain so you will better understand. A battery has a life 2, 3, 4 or more years depending on the rating. The life of a battery is determined by the lead plates inside. The plates shed material that ends up at the bottom of the battery cells until it shorts out a cell (battery life is over). The thicker the lead plates the longer the battery will last. It is easy to determine if a battery is bad by doing a load test and any battery shop will normally check your battery for free.

If the battery is shorted out in one or more cells it will draw large amounts of electrons from the alternator and not hold a charge very long. Replace it.

Your alternator can be checked by performing a ohms test on it. Again an automotive shop can test your alternator winding and slip rings. They can even run it on a “SUN” machine. This machine acts like you car engine turning the alternator and testing the out put pretty simple test. Another simple test is using a ohms meter test the output while the alternator is running and charging the battery. What you are looking for is voltage 12V going into the battery.

I would suggest you look at the top of your battery and see what date it was installed. It may be over due for a change by the year. At the very least take your car to a local shop and have them ohm the alternator while it is in the car, it only take a few second to know which one it is battery or alternator. Your local Sears will do this for free in most towns.

Answer 4

If the alternator was good, the car would still continue to run after jump starting it, as the electronics can run off the chargeing voltage from a good alternator. It is possible for a bad alt to take out a battery and vice versa, so they may both be bad. I would start out with an alternator. As far as the coolant and brake lights coming on that sounds like a non-related issue... Check the coolant and brake fluid levels-they may be low

Answer 5

As for the coolant and brake lights coming...check the radiator fluid as you may be low. Also get your brakes checked to see if there is a problem.

As for the car playing dead...check both the battery and alternator again. I just went through a similar problem and first had to replace the battery and then, abut a month later, the alternator. The battery may also need to have water added. Good luck.

Answer 6

With the engine running, put a multimeter on the battery leads. You should read about 13.6V. If you do then the alternator is fine.

With all options off, and the key out of the ignition, and doors shut, check the current draw on the battery. With that same multimeter, put it on the amp reading and pull one of the battery cables and put the meter in series between the battery and the cable. See if there is a drain on the current. Now you can pull fuses one at a time and when you lose the current drain that will be the bad circuit draining your battery down. good luck

Answer 7

3 different things to check.
1, be sure the battery is OK.
2,be sure alternator is OK/
3, have car checked for a parasitic draw. This can kill a battery over night. But it does sound like the alternator is bad.

Answer 8

Pop the caps off the battery and check to see if it is low on fluid, also while looking in there you will see six "cells" if any of the cells are bubbling that means the battery is bad, if it is low, fille it with distilled water, if all is well, take off the alternator and have it tested at a parts store.

Answer 9

Sorry man that sounds like you need a new alternator. If you took to autozone and they said it was good then its your alt. You could also take it to another parts store like Advance Auto Parts and let them test your battery. But im almost 100% sure its your alternator. Sorry man.

Answer 10

quick check with the car running remove the negative battery cable. If it quits the alternator is a problem.