Car Battery or Alternator??

[TurboQuattroPwr]

So I got in my car Saturday night to find out the car battery was dead (The car had been sitting all day). So, I got someone to jump the engine and right when I connected the jumpers my engine fan turned on immediately, which I thought to be weird. Anyways, I turned the car on immediately, no hesitation and away I went. Yesterday I took the battery to Pepboys, because again it was dead, and they charged the battery for me (Said the voltage was around 11 or so when I brought it in and they recovered 12) and tested it for free. The battery turned out to be "Good", so I took it back home and threw it in last night around 8pm. Right when I put the battery in the fan kicked on again and the hazard lights were flashing....no beeping at all. I took the car for a spin and everything seemed just fine. I wake up this morning and the thing's dead again!!! Does anyone have any ideas as to what's going wrong?? I don't understand what's draining it so quickly with the car off.

The battery is a Optima Red Top that I bought 08/2009. Also, everytime I restart the car, it reverts back to the default date and time (08/23/2001: 12:03 - lol).

Any suggestions would be great!!!

Thanks

[old guy]

Check for water in your ECU box. Sounds like your fans are running continuously even with the key off. Your ECU master control relay could be sitting in water and causing the fan control relay to become activated.

[TurboQuattroPwr]

Check for water in your ECU box. Sounds like your fans are running continuously even with the key off. Your ECU master control relay could be sitting in water and causing the fan control relay to become activated.

That could be, but when I shut the car off last night the fan was off. I went out to check it again an hour later and the fan wasn't on then either. Dunno.

[dubgli]

i think autozone or the like can test the alternator somehow. To me, it sounds like the alternator. You're basically only running on however much juice your battery is holding at the time.. Once you run out, it's dead and you repeat the cycle of recharging the battery.. Well you wouldn't have to keep recharging the battery that often if the alternator was working, doing its job. That's just my thought.

[Teratorn]

If the battery tested good, then it's either something is draining it while parked, or it's not charging while you're driving. After driving, can you restart the car immediately? If not, the alternator is not charging. Isn't there a dash light that would tell you that, though?

[TurboQuattroPwr]

If the battery tested good, then it's either something is draining it while parked, or it's not charging while you're driving. After driving, can you restart the car immediately? If not, the alternator is not charging. Isn't there a dash light that would tell you that, though?

After driving, the car will start immediately. It seems like after the car sits for long periods of time, the battery loses life....weird. Oh, and the battery light on the dash doesn't come on.

[JoshDub]

While the car is running disconnect the battery. If it dies, then its the alt.

[A4 Moda]

Trust me here. It's your battery. Don't freak out. Get a new battery, either another red top, or an OEM battery from Autozone, or the Auto Club. Your car will be fine.

Dry Cells have a tendency to internally short out. It's sporadic, and highly reactive to temperatures changes.

My guess is that your Pos (+) post has shorted out. First intermittently, (like you described), then one of these days, (soon) it will be permanent. It will completely drain everything out of your electrical system. Get a new battery, and you will be fine.

So again, get a new battery, and don't freak yourself out about getting a new alternator, or getting it rebuilt, or anything else.

If you are an autoclub member, have them come out and do a battery test for you. They check alternator, battery, and they even have an OBD II saver where they plug it in to save all your car settings, before they remove any hardware from your car (like the battery). They've got the equipment, so have them check it out for you.

GL.

[old guy]

I think that when you get to the bottom of everything it may be more than just the battery. If I understand you correctly you stated that on two occasions your battery was flat and when you hooked up the jumper cables you radiator fan immediately started running.

That is not normal. You need to get to the bottom of what is causing your fan to activate when the car is turned off. Something is energizing the fan relay which in turn could be what is draining your battery. The first place I would suggest looking is the ECU power control relay in the ECU box.

[Outerfroggy1]

old guy is right, this happened to me a few months ago. at first i thought it was the battery or alternator. until i got up for work one morning and my fans were running. turns out i had a crack in the ECU cover and about 2 inches of water on all the relays.

[alpinestar180]

is there a chance you hooked up the jumper cables backwards when you jumped your car? my mom did this on her lexus and the electronics (like the radiator fan and lights) were freaking out for weeks.

[BerNur]

im sorry to thread jack but is it ok to rebuild the stock alternator my alternator is going bad and i donno if i should rebuild it or just buy a new one.

[caligts]

im sorry to thread jack but is it ok to rebuild the stock alternator my alternator is going bad and i donno if i should rebuild it or just buy a new one.

In most cases you may be better off just buying a new Alternator. Rebuilding may only be the regulator but you'll also be paying the labor which for most auto electrics is $60-$80 per hour. Just buy a new one.