Battery drain

VHEFCON

MEMBER
2000 PONTIAC GRAND AM
4 CYL
AUTOMATIC
200,000 MILES

I let my dad borrow my car for a few months, well when I repossessed it he took the battery so I bought a new one. Now every time I try and start it it does not start. It’s completely drained nothing comes on. I have to jump it, when I connect battery cables it says otherwise voltage is 12.4 once I jump it, it stays on and is good to go. Also the power steering is out. Didn’t know if there was a connection between the two? And what can I do to fix this?

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

We need to do what is called a parasitic drain test. This is done by unhooking the negative battery cable and hook the voltage meter in line with the negative cable and the battery post.

https://www.2carpros.com/articles/car-battery-dead-overnight

This means you need you need to put one meter lead to the battery cable and the other to the battery post. Then set your meter to amperage and see what it says when the doors are all closed and lights off. It should be under 35 milliamps (.035 amps).

I suspect your vehicle will be higher then that so we then need to start pulling fuses to see when it drops to under this amount or basically 0. Then we will know what circuit is remaining on and draining the battery.

Also, the power steering is not going to be related to this so let's get a new post started for that issue and we can help with that as well.

Let's run through this and go from there.