Alternator not charging battery?

[danny19891]

Hi, i have a 06 grande punto and the alternator doesn't seem to be charging the battery.

I have had a new battery fitted also just had another second hand alternator fitted today but now even worse as the last alternator gave out a little charge (could jump the car and the engine would stay on whilst idling) with the new one fitted the car drives but cuts out if left idling long enough.

Is it possible that the second hand alternator i just bought and had fitted is also bad or is it possibly something else?

Thanks in advance.

 

[fingers99]

Just put a voltmeter (0-20 volts DC on a multimeter) across the battery:

a. engine off
b. engine running
c. engine running, all the electrics on.

Note down the voltages, report back.

One thing to check is that the thin wire from the alternator is connected (both ends). Without that, the battery/alternator light will stay on, and the alternator generally won't charge.