Alternator Whine, Not charging at Idle

[travis2ninja]

Hi,
In my 1992 Nissan TD27t Terrano the alternator decided to stop working which was a Genuine Hitachi 60amp.
I bought a new one from auto8, 80amp with vacuum pump and installed it.
While driving it charges fine, around 14.5volts.
But it makes a whining noise as soon as i touch the throttle, if i disconnect the plug at the back the whining noise stops but obviously doesn't charge at all.
It also does not charge while idling, only when it goes above ~1000rmp.
Which is pretty annoying since you want to use it while stopped so you don't drain your battery.
What do you think is wrong with it? and is it an easy fix or should i just send it back?
Cheers

[Colinl]

Alternators generally do not put out large amps to charge batteries when at idle. Alternator pulley speed needs to be around 2000 rpm to approach max output.

Idle up switch or resizing the alternator pulley would help.
Most alternators will handle pulley speeds around 10,000rpm.

Not sure about the whining noise though....

[evolution02]

Alternators don't charge much at idle but with all electrics off and wait for glow to turn off voltage should still be up a bit
The whine is a concern tho. Does it get hot fast? As in can't hold your hand on it?
At revs with everything on, heater, lights, rear demister etc does the voltage stay up around 14?
If not it could have a phase out due to blown diodes on the rectifier and I would be sending it back

[skidmark]

If not it could have a phase out due to blown diodes on the rectifier and I would be sending it back

+1 for what he said