Howdy Jimmy,

I think you have a loose or corroded connection.

I checked the voltage on the battery again and it was 12.5. When I turned on the car it was around 13.3. The alternator was again at 14.4- although it seemed to fluctuate quite a bit...

The differences in voltage in the circuit is the giveaway. Good, tight connections should not drop any significant voltage. When you read .8V difference between OFF and engine running at the battery you know the alternator is working. However, the voltage measured there is insufficient to charge the battery.

Moving to the back of the alternator, the voltage measured at B+ showed another 1.1V. That is a charging voltage.

The fluctuating voltage at the B+ is, I think, yet another symptom of a loose connection. As the load on the alternator is changing constantly through a loose or corroded connection, the alternator responds.

Then I turned on the windshield wipers, blinkers, lights, etc. and the voltage on the battery actually went up to between 14.0 and 14.2...

Excellent check. Yes, the alternator responded to the increased load with increased output. Your alternator is working.

Take a look at this:


This charging circuit pictogram is for an earlier model year but it is basically what you are dealing with on your car. Make sure that all the connections shown on that illustration are tight and corrosion free. Your car has a power distribution block (and a fuse?) next to the battery. Make sure all those connections are in good order too.

The ground side of that circuit is not shown in the illustration. Check the engine ground strap, the battery negative side cable, and the condition of the ground points where those cables connect. Let us know what you find.
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Mr. Shannon DeWolfe -- I've taken to using mister because my name misleads folks on the WWW. I am a 53 year old fat man. ;-)