voltage dropping to 12.5V with accessories on while coming to a stop

[S2G-Unit]

Last year I prematurely changed to a Denso Remanufactured alternator. Recently while adjusting my headlights for 15-20 minutes the battery died. I then paid more attention to the voltage in car.

While at idle with A/C, rear defog, lights, radio and cruise control on, sometimes voltage would drop to 12.5-13V. I bought a new battery and while at idle things start off ok. Although, if I go for a drive, stay in 2nd gear and roll to a stop I can see the voltage go down to 12-12.5v. I pulled over and the voltage stayed that way at idle. If i drove off again it rose back up to 14v.

Is that normal or should I rebuild my alternator?

 

[nikey22]

Last year I prematurely changed to a Denso Remanufactured alternator. Recently while adjusting my headlights for 15-20 minutes the battery died. I then paid more attention to the voltage in car.

While at idle with A/C, rear defog, lights, radio and cruise control on, sometimes voltage would drop to 12.5-13V. I bought a new battery and while at idle things start off ok. Although, if I go for a drive, stay in 2nd gear and roll to a stop I can see the voltage go down to 12-12.5v. I pulled over and the voltage stayed that way at idle. If i drove off again it rose back up to 14v.

Is that normal or should I rebuild my alternator?

The NSX alternator is a little unique.
The windings on the stator are stepped up to accommodate the higher Revs, even if the specific outputs are the same on your Denso, and even if the casing is the same.
Can you go back to your original alternator and try it out?
The original alternator ($1000) should last a very long time without issues.

 

[S2G-Unit]

The NSX alternator is a little unique.
The windings on the stator are stepped up to accommodate the higher Revs, even if the specific outputs are the same on your Denso, and even if the casing is the same.
Can you go back to your original alternator and try it out?
The original alternator ($1000) should last a very long time without issues.

well then, 1 year after changing the alternator I shouldn't have thrown it out last week!! (Car is a 94)
It actually seems fine, I may be overly paranoid now and watch the volt gauge far too much.

Just curious, I guess if voltage drops for everyone else as much when coming to a stop in 2nd gear.

 

[Larry Bastanza]

Just as a precaution, make sure you check the belt for tightness......

Regards,
LarryB

 

[S2G-Unit]

I ended up just buying a new battery. Everything is back to normal.