Crankshaft Position Sensor Question

Hi guys,
In the last 2 weeks, my 97 GTP has something abnormal.
Tachmemter will die sometime while car was running, it happened several times. I had 2 times, when I fully stopped before trafice light, check batter and check engine oil lights on, after then car could not move any more. For the first time, I restarted car, everything turned normal. For the second time, car could not start again. A guy nicely helped me to push car off road, and then I tried again, it started!!I posted in some other forums, some guys suggested crankshaft senor is gone, and battery/alternator is bad.

Last Saturday I sent it to dealership, they scanned to report Crankshaft senor was bad, and I had it replaced.

Now I have some questions
does only this sensor cause these problems? I tested battery while car was off, reading is 12.7V, I think it is normal; I started car, the reading is 15.08V (should it be 14.4V), is it too high? How can I tell if alternator is really good or bad by myself?
Thanks for any suggestion!!

on my 98 it reads aroung 15v too. it's been like that for years. i wouldnt worry about it. i havent had any problems with it being that high.

Those are the classic symptoms associated with the cps.

You should be good to go now...

That is a good sign. You have a good altenator. Under load High beams on, stereo blasting it may pull down to that 14V. Crank sensors when bad do cause havoc.