I was going to replace my key fob battery so I took the battery out. Then I went to go start my car and it just kept turning but would not start up.

I put my fob back together with the battery and it is still doing the same. I tried to switch to neutral to see if that would do anything. It didn't. So I put my car back in park. However, the parking brakes are not on, even though the Park gear is selected. Any ideas?

 

I think you may have to get your key programed for it to work. I will try find the procedure in doing this for you

 

dead car battery or bad alternator? changing just the battery in your key should not effect the car.