I saved and got her a 99 outback and a month later the battery and brake light come on and off. It always starts right up when cold but after a 20 min drive it will just crank and crank. When it cools it will start right back up. I ran the codes and the only thing that came up was the Fuel temp sensor. And I also forgot to say the headlights vary in brightness while driving but have never had a low battery problem and all this stuff varies in regularity. Could it all be related and is there any test I could perform? I need to try and avoid a shop we are both broke. Any help would be great I have a meter and most tools.