A failed sensor lead - normally the one that feeds the bulb in the dash can cause the symptoms you describe. Or when the bulb is dead - same situation. The regulator doesn't get enough power to work at lower speeds. when you rev it higher, the remaining magnetism produces enough voltage to make the regulator work and then keeps it running. I have seen this on my buddys car and also read it in an automotive book. So - start by looking if the battery-bulb in the dash works how ist should be. Elvis What kind of alternator do you have? I've heard of this issue on some aftermarket units, just wondering. Dave Swingle --- In dmcnews@xxxxxxxxxxxxxxx, "valleyrat12" <valleyrat12@xxxx> wrote: > > Gee I'm posting here a lot... > > OK, I noticed while my car is idling right after it is started that > my battery voltage is low, below the 14 or so volts it should read > when running. If I rev the engine the meter will suddenly bounce up > to where it should be and continue even when the engine runs back > down to idle, indicating that the alternator is working. Also, a > whirring sound can be heard from the alternator AFTER the gauge > indicates that it is working. I have cleaned all of the contacts and > the condition persists. > > I have noticed this on other cars and assume that the sound is > normal, but I assume that my alternator is dieing. What would cause > the alternator to work only after the engine is revved up to 3000 > rpm? Also, there are some wires (2) that are hanging down by the > alternator that are not hooked up, Black/Green I think. > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/