Hello everybody,
I have a good one for you.I fully charged my battery,placed it in the car,started it up,the gauge read a little over 13V. The more the engine ran the LOWER the reading would go!(leveled off at around 12V).
So I would check the battery with VOM meter and it would say 14.6V;check inside the car-less than 12.5V(no acc. on).
I put up the headlights the gauge drops the engine idle goes down slightly,first thought bad alternator or pully tensioner is done or the belt is stretched.
Anybody ever encounter this problem?
Sure would appreciate the help!!!!
Thanks !

 

alternators going, replace it soon it will crap out at the worst time

 

Well normally an alternator will charge in the 14.5V neighborhood.. Between 14v and 14.5v... I think as your battery approaches a maximum charge, say if your batt is brand new and holding charge very well....the alternator will cut output so as to not overload the battery....and will just up output as needed for accessories. But still, if you're dipping as low as 12v.....I'd say it's a bad alt. 12 volts is absolute minimum to keep your car running. Anything less and you're draining the battery, which will kill your battery quite nicely and eventually the car will just shut off and not crank to restart.

 

Check the voltage at the alternator and compare it to the voltage at the battery.