I really thought I've been on Al Gore's internet long enough to squash this rumor
DO NOT do this!!!! The newer the car, and the more electronics, the better the chance that you'll "kill" some electronics, whether it's part of the EFI, the ignition, or the great big stereo
(Of course if it really is NOT charging, then it won't hurt, but it really does not prove anything, either)
Doing so and having the engine die, also might mean that it simply was idling slow enough, and had enough load, that it could not "keep up."
There are simple tests to show whether the alternator is charging.
Start with this:
Identify the green and blue field wires. Remove the green wire and hook a clip lead from the disconnected alternator field terminal to ground. Start the engine, bring up RPM and see if it charges
If not, take a multimeter (or even a test lamp) and with the key "in run" see if there is power on the blue field wire.
If so, check voltage at the battery, and at the alternator output stud with the engine running at a good fast idle. If they are exactly the same, and below 13.5 volts, the alternator is not charging.
If the battery is below 13.5, but the alternator stud is quite a bit higher, then you have a wiring problem in the charging line from the alternator to the battery.
