could be battery-put headlights on try to start,see if headlights go dim ,if so battery is problem [could be charging fault] if they stay bright then it may be starter or engine earth fault, if so try connecting just one jump lead on to battery negative (-) and the other end of the same jump lead to engine ie, cyl headbolt or engine lifting bracket etc... if starter works this way then engine earth lead is at fault. (MAKE SURE YOU ONLY CONNECT NEGATIVE LEAD TO ENGINE METALWORK USING ONE JUMP LEAD ONLY) hope this helps
k, March 2008