Roughly every 3 months my battery dies, I take it to advance auto parts and they give me a new one since its still under warranty. I use their expensive titanium gold brand whatever the hell it’s called. They always test the battery, starter, and alternator and it’s always the battery. This is probably the 6th one I’ve been thru. The alternator was changed less than a year ago with one from Autozone. Yesterday my car started to show its typical symptoms again; radio and radar turn off then on, dim headlights, lag in acceleration around 1000 rpms. I took it in, they ran their test, said everything was fine. I suspect I just have to wait a few days, then take it in, when it’s more drained. Here were the results of the last test:
Battery – Voltage: 12.59 V
Measured: 750 CCA
Rated: 640 CCA
Starter – Voltage: 10.95 V
Amps: 266.0 A
Time: 687 mS
Alternator – no load: 13.87 V, 13.4 A
load: 13.78 V, 4.5 A
What could be causing this problem? I don’t have a sound system, unless a 200 watt headunit counts. I read something about a grounding kit; would that do anything? I suspect there’s a problem with the alternator if it’s not charging the battery and the electronics should be running off of the alternator after the car starts; but then why would the alternator test good?
maybe it's not grounding well enough? just a stab in the dark, buy a grounding kit off the internet? Last time i was looking at that stuff the blemco(blehmco?) grounding kit came to mind.
Obviously, just because the battery went dead doesn't mean that the battery is bad. I mean, as long as a battery can hold a good charge, and supply all the electronics, the battery is fine. There are really two things, in my mind, that would cause a low charge on the battery,
1. A very heavy load that is basically turning off the alternator. This will slowly starts to drain the battery.
2. An alternator that is not coming ON or is getting cut off from the system.
I'm more inclined to think that it is because of item #2. In which case this could be coming about during the startup of the engine. In this stage, the battery charge light serves a major function into getting the alternator kick started into operations.
The other thing I can think of is that the battery sense line is dropping out and the alternator doesn't have its feedback voltage to continue charging the battery properly.
Of course your tests doesn't show any problems because it is working properly. So this sounds like an intermittent electrical charging issue. One way to identify the problem is to have a voltmeter hooked up to the cigarette lighter while you driving normally, and then from time to time, check to see if the voltage drops below 12V and stays there for a long time. That will tell you that the alternator is pretty much shut off and not charging. Turn off some electrical loads to see if the alternator can recover back to normal.
If the low battery charge voltage occurs during engine startup then you know that the alternator is not kicking in.
You are going to have to drive like this for a while until you can identify when the problem occurs so you can run some more tests. You have a very challenging problem at hand. Glad it was you and not me.
I stopped reading when you said Autozone alternator. I burned 19 of those.
I recall someone said that before. Why would you go through 19 and not stop around 3? I’m aware of their lifetime warranty, but wouldn’t you want to drop the hassle of installing 19?
Obviously, just because the battery went dead doesn't mean that the battery is bad. I mean, as long as a battery can hold a good charge, and supply all the electronics, the battery is fine. There are really two things, in my mind, that would cause a low charge on the battery,
1. A very heavy load that is basically turning off the alternator. This will slowly starts to drain the battery.
2. An alternator that is not coming ON or is getting cut off from the system.
I'm more inclined to think that it is because of item #2. In which case this could be coming about during the startup of the engine. In this stage, the battery charge light serves a major function into getting the alternator kick started into operations.
The other thing I can think of is that the battery sense line is dropping out and the alternator doesn't have its feedback voltage to continue charging the battery properly.
Of course your tests doesn't show any problems because it is working properly. So this sounds like an intermittent electrical charging issue. One way to identify the problem is to have a voltmeter hooked up to the cigarette lighter while you driving normally, and then from time to time, check to see if the voltage drops below 12V and stays there for a long time. That will tell you that the alternator is pretty much shut off and not charging. Turn off some electrical loads to see if the alternator can recover back to normal.
If the low battery charge voltage occurs during engine startup then you know that the alternator is not kicking in.
You are going to have to drive like this for a while until you can identify when the problem occurs so you can run some more tests. You have a very challenging problem at hand. Glad it was you and not me.
I'll be hooking up the voltmeter this weekend. But, I was thinking, if the alternator shuts off while im driving, then the components will run off of the battery which continues to put out 12volts. Therefore, would the voltmeter not continue to read 12 volts regardless if the alternator is off or on? Even though the source changes (alternator / battery) the voltage read on the voltmeter would remain the same... is this theroy wrong?
No, the theory is this. When the alternator is working correctly and it is strong you should sense something like 13.8v-14.2V. With the voltmeter placed across the battery terminals that is what you should normally read. As you start to run some heavy electrical loads the voltage across the battery terminals will be less. Why? Because the alternator is supplying those heavy loads and is giving very little current to the battery. The battery will also start to output some of its charge out to the loads. If the voltage ever drops below 12V and stays there for a prolonged period of time then you know that the battery is discharging heavily and alternator is basically not doing its function. So the idea would be to identify what electrical load(s) is causing the battery voltage to drop below 12V and remain there. Eventually, you'll reach the point where the battery will drain or hold very small charge, not even enough to crank the engine. So get the voltmeter readings and lets see if something stands out from the tests.
I am sure you have already checked all this stuff, but check the simple stuff first. First check battery cable condition, check the serpentin belt to make sure it is not loose or too tight. Look and see if your door trigger light is not broke off causing it to draw juice. Just a few suggestions, good luck. It always seems to be the simplest solution with these old cars.
if you haven't already replace your battery terminals.. I am sure by now they are corroded to all can be.. I have a similar but maybe different issue.. its harder for me as I have over 3kw in my car and 3 batts so I have to unhook everything...
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