[Mustang1989]

I've got an '05 F250 with 125k miles that wont start this morning. It's completely stock except for exhaust. I went outside to start it, and it cranks, but won't start. It worked just fine yesterday going to and from work. On my way home yesterday I was nearly empty, and filled the tank half-way. Bad fuel maybe? I checked my fuses, and their all good. I'm not sure about the relays. My batteries are at 8.5 and 9v while not running. Is that too low?

Thanks