car wont start after new battery fitted
 

2008 a4 advent s-line I have fitted a new battery and since car wont start . when I turn key in ignition all the dash lights just starts flashing real fast but car wont crank over . I have disconnected battery neg lead a few times but some times when reconnected it justy kills all power when key turned other times just all light flkash crazy thanks inadvance kenny:!::!: