Battery dies withen 8 hours.

Hey, I'm new to the thread and am having a serious issue. First off I have a new battery and my alternator tested good, but the red battery light is still coming on, when the car starts that is. The other day I was driving home and plugged in both my cell phone and and electronic cigaret charger to my cigarette lighter (have a dual usb plugin for one lighter) and all of the lights on my instrument panel started flashing and i noticed my car starting to act funny so I unplugged everything and made it home. The next day my car started fine but after driving for about three minutes my car died completely. So I went and got a new battery and put it in. After this my car ran perfectly and I went to work. But, after work I started my car and started to drive, again my car drove for a few minutes then died. Today I put in yet another new battery and had the alternator checked. Both are fine. What could be causing my red batter light to come on and what could be draining my battery within a few hours, or is it a charging issue? I'm stumped. Thanks in advance for any help or advice.

If your charging system is OK, check the FSU. Many posts about it on many forums including this one. Search is your friend.

Originally Posted by Bumish1

Hey, I'm new to the thread and am having a serious issue. First off I have a new battery and my alternator tested good, but the red battery light is still coming on, when the car starts that is. The other day I was driving home and plugged in both my cell phone and and electronic cigaret charger to my cigarette lighter (have a dual usb plugin for one lighter) and all of the lights on my instrument panel started flashing and i noticed my car starting to act funny so I unplugged everything and made it home. The next day my car started fine but after driving for about three minutes my car died completely. So I went and got a new battery and put it in. After this my car ran perfectly and I went to work. But, after work I started my car and started to drive, again my car drove for a few minutes then died. Today I put in yet another new battery and had the alternator checked. Both are fine. What could be causing my red batter light to come on and what could be draining my battery within a few hours, or is it a charging issue? I'm stumped. Thanks in advance for any help or advice.

How and who check your alternator? I think your alternator is still the culprit. Do yourself a favor, what is the voltage reading across the battery when you're idling? It has to be above 13.5 V

Originally Posted by 16valex

How and who check your alternator? I think your alternator is still the culprit. Do yourself a favor, what is the voltage reading across the battery when you're idling? It has to be above 13.5 V

+1, recheck alternator performance.

Originally Posted by 16valex

How and who check your alternator? I think your alternator is still the culprit. Do yourself a favor, what is the voltage reading across the battery when you're idling? It has to be above 13.5 V

After I replaced the battery, for $160, and it still died I instantly thought it was the alternator and tore it out. After I had it out I went to Autozone to have them test it. They tested it three times on their machine and it passed all three times. I'm going to bust out the multimeter today and check all the fuses. I think I might have shorted something or put to much draw on something when I plugged in everything to my car. I've seen the FSU threads and nothing in my car stays on. That's why I didn't think it was the FSU.

Originally Posted by Bumish1

After I replaced the battery, for $160, and it still died I instantly thought it was the alternator and tore it out. After I had it out I went to Autozone to have them test it. They tested it three times on their machine and it passed all three times. I'm going to bust out the multimeter today and check all the fuses. I think I might have shorted something or put to much draw on something when I plugged in everything to my car. I've seen the FSU threads and nothing in my car stays on. That's why I didn't think it was the FSU.

I thought the same when my FSU bit the dust 3 years ago. I caught the sucker by chance, had to go in the garage after about 4-5 hours after I parked the car, and I heard a noise coming from the car. the blower was going full tilt!!!!!
The car was quiet as mouse when i left it.

Okay so here's the update. I put the alternator back into the car, hooked the battery up, and drove to Autozone to have them test the charging system with everything in place. On the way there no red battery light. Once I turned the car on to have the charging system checked the red battery light turned on. The same alternator that passed all three tests ,three different times, failed once it was hooked up to the car. I went home and let my car sit for 20 min, to get it into "sleep mode", then I hooked up my fuse tester and all of the fuses in the trunk by the battery were still reading hot (the sucker lit up like a candle on every fuse). Oh and my battery was at 12.27 running amps. Isn't it supposed to be 13.75 or 14.00? Is there any way I can test the FSU before buying a new one and sticking it in there? Also I noticed an intermittent problem where the blower, for the hvac, on my car just doesn't turn on; could this be the FSU problem that is draining my battery?

Battery voltage should be 12.6 V when fully charged without the engine running. When the engine is running, the voltage across the battery terminals should in the 13.8-14.4 V range.

If the HVAC blower is not responding to the controls correctly, there's a good chance the FSU is bad.

Okay I just pulled out my FSU. Can I drive my car without this in? Also If it is the FSU tomorrow when I go to turn my car on will the issue be solved, or will my battery still drain over night with the FSU pulled out? Also when I went out to my car to remove the FSU I turned it on, before removing the fsu, and could hear a clicking sound coming from the front of the car near the vents. The clicking sound continued the whole time my car was on and for a while after I turned the car off.

Originally Posted by Bumish1

Oh and my battery was at 12.27 running amps. Isn't it supposed to be 13.75 or 14.00? Is there any way I can test the FSU before buying a new one and sticking it in there? Also I noticed an intermittent problem where the blower, for the hvac, on my car just doesn't turn on; could this be the FSU problem that is draining my battery?

The V should be 13.5V+ when the car is running.
No, there is no test for FSU functionality.
The intermittent problem with your blower is the BEST indicator that you have an FSU problem.

Originally Posted by Bumish1

Okay I just pulled out my FSU. Can I drive my car without this in? Also If it is the FSU tomorrow when I go to turn my car on will the issue be solved, or will my battery still drain over night with the FSU pulled out? Also when I went out to my car to remove the FSU I turned it on, before removing the fsu, and could hear a clicking sound coming from the front of the car near the vents. The clicking sound continued the whole time my car was on and for a while after I turned the car off.

Yes, you can drive without the FSU. However, you will have no HVAC fan control.
If the FSU is the cause, removing the FSU should eliminate the battery draining problem.
Not sure what the clicking is. Could be related to the FSU.

Lastly, get your FSU from the dealer. You will pay more but there have been a noticeable amount of premature FSU failures associated with aftermarket FSUs. The risk reduction is worth the additional cost.

So I have an update. I pulled out my FSU and my car worked for the past four days. However, the battery light was still on. When I was on my way to work today my car died again, this time without the FSU in the car. What else could cause my battery light to turn on and my battery to die? I tested the alternator while it was out of the vehicle at Autozone and it tested good twice. When I put a new battery in and put the alternator back in the alternator tested bad and my running amps were only 12.27. If it's not the FSU causing my battery drain and power loss what could it be?

Well, if it looks like a duck, walks like a duck, and quacks like a duck... trust your gut...it's your alternator.

Red battery light illuminated and making less than 13.5vdc with the engine running = bad alternator.

I've seen many alternators over the years test good on the bench and not work correctly for one reason or another unless it's actually something damaged/broken in your alternator wiring connector...

Originally Posted by Bumish1

So I have an update. I pulled out my FSU and my car worked for the past four days. However, the battery light was still on. When I was on my way to work today my car died again, this time without the FSU in the car. What else could cause my battery light to turn on and my battery to die? I tested the alternator while it was out of the vehicle at Autozone and it tested good twice. When I put a new battery in and put the alternator back in the alternator tested bad and my running amps were only 12.27. If it's not the FSU causing my battery drain and power loss what could it be?

That voltage is way too low. Check the battery clamps to make sure their nice and tight. Get the battery tested. If all the above are ok, it is most likely alternator that is failing.

Originally Posted by Bumish1

What else could cause my battery light to turn on and my battery to die?

While I have trouble with the statement that you replaced two batteries, either way, in a case like this, you have to follow the trail of breadcrumbs.

Let's assume you are correct that the alternator and battery are new and therefore supposedly good (especially as both apparently test as being good).

Then, why would you still get a red warning light? That light indicates that the charging system isn't working, so, in a case like this, you have to follow the breadcrumbs.

Start at a known good working point, such as the output from the alternator, and work your way forward, until the bad component shows itself. I'm pretty sure the alternator itself is the bad component, but, if you measure the right voltage at its output, then you'll just have to start following those breadcrumbs.

EDIT: Here's a picture of my charging voltage done by Autozone yesterday from this thread where my battery dies within 8 hours.
(Note that this 14.13 volt reading was at idle.)