Sorry for the delay in responding.
Lets back up a minute. The alternator recharges the battery when the engine is running. To say it's not charging would imply the engine was running when it was being tested. To say it's discharging could mean exactly the same thing or it could mean anything that is working, like lights and horn, is discharging the battery. Can I guess the engine started and ran once the new battery was installed? If that is right, can you put your hands on an inexpensive digital voltmeter? Harbor Freight Tools has them on sale all the time for 5 bucks or less.
We need the engine running to do the tests, and you will need to take 6 voltage readings; four with the engine running, and two with it off. Those readings with the engine running are: 1) right across the battery, 2) the large output wire bolted to the back of the alternator, 3, 4) the two smaller wires bolted to the back of the alternator. There will be a small black plastic block on the back with all three wires going into it, and two tiny nuts on tabs for those two small wires. You must measure right on those two little nuts, but if they're rusty, (like normal), you'll have to scratch them with the meter probes to get a good reading.
With the engine off just remeasure the battery voltage and the voltage on the large output wire bolted on the back of the alternator.
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Saturday, November 10th, 2012 AT 5:22 AM