Please help! We have an Audi A4 2.0 TDI 2006. I popped out in it earlier and when I stopped the radiator fan came on. Got back in to go home and same again but stayed on for ages. It drained the battery so car wouldn't start. Took out the fuse for the fan which stopped that. Got the car jump started and left it running outside the house. Went back out and it had cut out. Now it will turn over but won't start and help would be most appreciated!