Battery keeps draining

HALEYNAU

MEMBER
2012 VOLKSWAGEN PASSAT
180,000 MILES

So, my car was making a weird noise as if the pulley was going out. Then it stopped completely a few days later but then the car battery drained. Next day it started right up with no jump needed but the noise came back. So, I left it alone for a week or so until I could have my dad look, it was completely drained again, we jumped it, let it run, noise never started back up, and the car ran that whole day and then I went to the store the next day, by the time I got home the battery was drained again. A week later I attempted to see if it would start, and it did. What could this issue be? It doesn’t make that noise anymore though.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

First, make sure the accessory drive belt on the engine is attached and tight. I attached a pic below showing the routing and highlighted where the alternator is located.

Next, I need you to recharge the battery, so it has a good charge. Here is a link to help:

https://www.2carpros.com/articles/how-to-charge-your-car-battery

Once it is charged, we need to check the alternator output which is simple to do. All you will need is a voltmeter or multimeter. Here is a link showing how it's done:

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Based on your description, it sounds like the battery isn't being recharged. The link above will tell us.

Let me know what you find.

Joe

See pic below.

Image (Click to make bigger)