quick alternator question...

ok...i know my alternator is bad and i need a new one. i think it measured at 12.29 volts this morning. this may seem like such a stupid question, but is this low enough to make the dash lights light up? my battery was draining pretty fast, but it was about 6 years old, so i got a new one. how many volts is the car supposed to be running when in park and idling??

[Beav]

14.2 is optimal, 13.8-14.7 is acceptable. Dash lights sometimes come on because of a backfeed through the alternator when it goes bad.

[Trevor]

You may need to raise the revs. above idle to register full charge volts. Mine sits on 13.9 v. with a fully charged battery.