First of all the battery needs to be checked to see if ti is ok, if not replace it,If the battery turns out to be ok,then you need to check the terminals,on the battery,and check the earth lead that goes from the battery to the body,make sure there is no corrosion,if that is ok ,then you need to check all the fuses in the fuse box to the right of the battery ,you will need to remove the black plastic cover,also try to remove the fuses and check the terminals for corrosion,and then if still nothing found you will need,seek further diagnosis,hope this helps.
mark, November 2008