Pretty sure this isn't normal. With engine off, keys out, my alternator hums ever so quitely. I'm suspecting this of killing the battery if it isn't ran every other day. Anyone ever had this problem and what can I do to stop this.

 

Still havn't found the cure for this. I've looked at the wiring diagrams and looks correct but I've been wrong before. I'm holding 13-14 volts with engine running. It's not very noticeable, if any background noise is going you can't hear it. This is driving me nuts help, please, somebody, anybody.

 

same here.

my understanding is the regulator in the alternator is drawing power off the battery.

if you have a weakened battery and you let the car sit for a few days it makes cold starts harder and sometimes impossible.

i am not sure if it is due to faulty wiring or a faulty alternator.

when i popped off the two wire harness on my alternator, it accidentally grounded on the metal and sparked. i was under the impression this shouldn't happen when the ignition is in the off position.

so maybe the wiring is fagazy.

maybe i need a new alternator.