Alternator...?

I

Ickaber

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Hey guys,

My 2000 LS (3.0L V6) threw a bunch of lights on the display the other day (traction control, ABS, air bag, and lamp out indicator) and then died. My daughter was driving it, so I went to get her and jumped it, it fired right up and I drove it home. I checked the battery and it was low, so I put it on the charger overnight. The car fired right up the next morning and we were able to drive it around town for a few short trips when it did the exact same thing again.

This time, to get it home I'd charge it for about 5 minutes with jumper cables from the other car, and then could drive for a couple of miles before it died again. I had to do that about 3 times to get home.

I took the battery out and went and got it tested and it tested bad. It was 14.5 years old, so I wasn't too surprised. It was a vented Motorcraft Tested Tough MAX rated at 650 CCA. The guy at O'Reilly asked me if I wanted to buy a new battery and I told him that I only wanted another Motorcraft, but it turns out they carried some. I ended up buying a non-vented Motorcraft Tested Tough MAX rated at 850 CCA. I put it in the car it was great for two days, and then did the same thing all over again.

During all of this, I had put a voltmeter on the battery with the car running and could see I was over 14V, so figured the alternator was charging okay. I did that several times. But, last night when I got it home after it died again, I put the voltmeter on the battery with the car off and it showed a little over 11V. So, then I started the car again (yes, on only 11V) and put the voltmeter on and the voltage stayed just over 11V, so it seemed the alternator wasn't sending any juice to the battery.

But, this morning I started the car after the battery had charged all night. With the car not running, the battery was showing just over 13V. Then I started it, and it went up over 14V again.

I'm guessing the alternator is going out intermittently, but wanted to see what you guys think. I haven't had a chance to climb under yet and check for loose connections or anything. But what's more likely, loose connection or alternator failing? And, I see that it's normally recommended to replace the battey and alternator at the same time.

Thanks for any thoughts.
 
Definitely alternator, you did all the right tests. Now stop killing batteries! Especially if they are unvented - undercharging batteries is damaging them.

I feel like if it was a loose connection - it would be at the battery, and since you have been jumping and changing out the battery, I would assume you were solid on at least that point.
 
if one fails = replace both... or spend then next few years replacing them back and forth
 
Andrizzle said:
Definitely alternator, you did all the right tests. Now stop killing batteries! Especially if they are unvented - undercharging batteries is damaging them.

I feel like if it was a loose connection - it would be at the battery, and since you have been jumping and changing out the battery, I would assume you were solid on at least that point.
Click to expand...

The battery connections are tight. I was thinking more at the alternator or something.
 
Thanks Andrizzle and G-RELL. I just wanted to do a sanity check and make sure I was thinking of this the right way. Calling the dealer now.
 
G-RELL said:
if one fails = replace both... or spend then next few years replacing them back and forth
Click to expand...

If the battery just fails all at once out of the blue then I just replace the battery. This is the kind of failure where car is running fine, park for lunch, come out, battery completely flat/dead. In other words, the battery just shorts out and fails internally of it's own accord. The alternator usually doesn't have much to do with it. I always do an on-car alternator test afterwards though to double check.

But if the battery won't stay charged, or I get flickering lights, or other weird electrical issues, then I replace them both.
 
Ickaber said:
... It was a vented Motorcraft Tested Tough MAX rated at 650 CCA. ... I ended up buying a non-vented Motorcraft Tested Tough MAX rated at 850 CCA. ...
Click to expand...

All Lead Acid (which is all 12V car batteries, including Optima) batteries are vented. They really have only two choices, vent or explode. Every battery manufacturer chooses vent.
I am assuming that what you mean is that one of the batteries had a vent tube connection which was connected to the tube that vents any hydrogen outside of the car, and that the other battery didn't have the connection, so it just vents hydrogen and corrosive gases inside the trunk. If that is what you have now, that is very bad. Not only is it unsafe, but it will also do damage to the electrical/electronic items in the trunk.
 
Installing an unvented battery in the trunk, a tightly sealed box, is a SIGNIFICANT safety issue. Please don't let anyone tell you otherwise. The guy selling you the battery is what, a guy selling autoparts. No disrespect intended, but he isn't working in a highly skilled job. And, he may be well intended, but probably doesn't really understand how batteries work and the chemical reactions involved.

So, please be safe, return the sealed battery and buy the right one for your application. Connect the vent as designed and built.
 
RJLipscomb said:
Installing an unvented battery in the trunk, a tightly sealed box, is a SIGNIFICANT safety issue. Please don't let anyone tell you otherwise. The guy selling you the battery is what, a guy selling autoparts. No disrespect intended, but he isn't working in a highly skilled job. And, he may be well intended, but probably doesn't really understand how batteries work and the chemical reactions involved.

So, please be safe, return the sealed battery and buy the right one for your application. Connect the vent as designed and built.
Click to expand...

It's possible Ickaber walked in with a group size and CCA rating. But I'd guess the parts finder system used depends on the owner knowing if they need vented or not...
 
I recently bought a Motorcraft BXT-66-750 CCA from the local Ford Dealership for $120. It's vented and the recommended battery for the car. Well, actually, I think the 650 CCA is the original battery.

I trust Ford parts.
 
Telco said:
And it's actually quite competitively priced to the parts store batteries, surprising for a dealer.
Click to expand...

The motorcraft battery from a Ford dealer here is about $15 cheaper then the autoparts store. Only problem really is that an auto parts store is 5-minutes down the road for me and a Ford dealer is 20 minutes. Convenience trumps price when your battery dies after you eat lunch :)
 
Thanks for the heads up and warnings everyone. I'll get that battery swapped out ASAP.

And, alternator went in Saturday morning. Pretty easy job on this car.

Thanks again!
 
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