Alternator or Battery

1996 Ford Taurus 3.0 V6 196,000 miles:

I noticed last night that my dash lights looked awfully dim, but didn’t think anything of it. Tried to go to work this morning and battery light came on. Under heavy rain or hitting huge puddles of water makes my battery light come on before and then it goes away. (This is not recent, I’ve noticed that in the 7 years of having this car) Now back to this morning, battery light comes on, then tach goes to zero but I can still accelerate, then the radio starts screeching and everything died. I pulled off quickly and called my wife to come get me. I sit a couple mintues ansd decided I’d try to get off this county road and a mile and a half back to the nearest town so I can hook up the tow rope in city and not on country road. Well, I got car started and got going and a mile later it goes dead again but I am able to coast into nearest town.

I think the battery is 2 or 3 years old, but I am not sure if its under warranty. I’ve not replaced alternator since I’ve owned it. We got the car when it had 75,000 miles on it. I’ve only replaced transmission and heater system.

I’m not sure I’d be able to get it to a parts store to get charging system tested. I could probably borrow a friends trailer but I wanted to get opinions on which it may be. What can I look for that is a pretty good indicator of which one it is. My guess is alternator since my parents car did same thing, but everything dimmed at same time and a cop happened to be behind them when it happened. He said he saw their taillights just go dim and then off.

If you have questions to further diagnostic capabilities, let me know.

Thanks for your time.

You can get your battery tested for free at most auto parts stores. Can you remove the battery and haul it there so they can test it?

Clean off your battery connections really well with a steel brush. If you are able to follow where those connections go, check the other sides as well.
If you have* a volt meter, measure across the battery. With the car running, it should be over 14 volts or so, if the alternator is doing the job.

*If you don’t have a voltmeter, you can buy one at HarborFreight for less than $10.

When hitting water and seeing the battery light come on, does the steering get more difficult? You may have a weak tensioner, a failing belt, a damaged/missing fender liner or some combination.

I will add that some Taurus models had a body round hidden under the radiator shroud that would fail and cause all manner of intermittent electrical problems.

I think Rod Knox is probably on target. The symptoms you describe sound to me like you have a loose belt and the moisture is making it slip. I’d bet that’s the problem.

I believe that should be “body ground,” an electrical connection. It is worth checking out.

Are you sure it was the radio screeching? I’m inclined to suspect that either a serpentine belt, a tensioner, or the alternator has crapped out. I think that last mile you got out of it the engine was running on what little juice was left in the battery.

Thanks SteveF. My bi-focals are getting old and my fingers thick.

Get the car started… Then loosen the positive batt cable clamp and pull the positive battery cable OFF of the battery… If the engine DIES immediately… You alternator isn’t working. If it stays running…it IS functioning properly…and the issue lies somewhere else.

If you say that the Batt light illuminates in association with puddles…then this suggests that you may be missing a plastic Belly shroud under your vehicle…allowing puddles/water to reach the alternator while driving…this isn’t a good thing…Alternators don’t like being hosed down while they are generating A/C power and then trying to convert it to 12 D/C IN FACT Alternators HATE this…so… Please let us know if you may be missing a belly pan/shield on the car…and if so replace it. Also please tell us where (physically) the alternator is located on this engine ( I dont feel like looking it up at the moment, LOL)…I am guessing that it is located Down Low perhaps…No?


Get the car started… Then loosen the positive batt cable clamp and pull the positive
battery cable OFF of the battery…

While I usually agree with Honda Blackbird, this is one where I respectfully disagree.
Disconnecting the battery with an engine running can damage the vehicle’s electrical components.

Alternators can and do produce voltage spikes. When the battery is connected, it acts like a big capacitor and absorbs those spikes - so that they never show up. Without the battery, those spikes will exist and will risk damage to the vehicle’s electrical system.

  • 1 TO Joe, he is 100% correct with all due respect to MR. Blackbird :slight_smile:

To Mr. BlackBird’s credit I belive he is right about your splash shield, eather that or you have a loose battery connection/ground somewhere and when it gets wet it goes haywire.

Yes, that can happen/is true, but its no danger in a 96’ Ford Tortoise… I wouldn’t suggest it in a 10’ BMW per say…but in this case he will be just fine… Besides…the car is going to immediately shut off when he does it anyway :wink:

Good call tho… I’ve seen this done more than 100X with no issues…(most x the alt was dead anywho) Its also no worse than having a stone cold dead battery in the car… But with respect to your comments, yes you are correct. I have no worries about this regarding this vehicle…and have done it on this very car before, several X…no probs

Now I wouldn’t do it in a really technologically/electronic laden new vehicle however…


As Blackbird said, you might have a belly shroud missing, anyway the belt is probably loose and water just makes it worse. I’d bet it is not charging enough, not the battery.