Try and jump start it at the motor not the battery, if you havnt tried it already.
That will narrow the problem down.
If its a vj they do have problems with earth cable at the battery.
You will have to remove the battery to see it.
you can test it by using a jump leed from the negative of your battery to seat belt mounting bolt,a wheel nut or any good earth you can find.
Check your main fuses under the bonnett.
Good luck
Mark, October 2011