When the alternator in a vw jetta vr6 01 isn't working ok, which light turns on (check eng.or battery light?)?

Question

because the battery was replace 1 month ago (brand new) and it's getting down.

Answer 1

battery light

Answer 2

Battery light.

Easy way to check the alternator, start the car, when its running disconnect the neg battery cable, if it dies or idles poorly, then the alternator is bad.

Answer 3

fist put key on check if batt light is on

if yes then start engine

light must  go off

that tell power to alt is there

that system work ok

u may have bad alt but check if nothing stay on fist

vr6 pain to work on  

ps running car batt post diconected not good for electronic  ignition  

u cauld be charging 12.5 volt  but need a least 13.8 to charge batt + assesory