i relocated my battery to the boot in my vl turbo recently and tidied the wiring in the bay a bit and once i finished it all went to start it and no go so i stuffed around for a bit looking at wiring diagrams in the workshop manual and found out that the reverse polarity relay was hooked up wrong, well it was hooked up right to what the manual said but when i connected the earth of the relay to the body it wont start but when i disconnect the earth for the relay the car starts and runs fine has anyone had this problem before???

Problem solved, car starts.

haha yeah but i was just wonderin if it has happened to anyone

You must be missing the diode that is hidden in the earth wire or it has gone short circuit. When the battery is connected properly, the relay is never switched on because the diode blocks current flow. The power to the ecu and injectors is fed through the normally closed contacts of the relay, therefore power is always fed to them. When you connect the battery in reverse, the diode allows current flow and the relay coil is activated. The N/C contacts therefore open and power is lost to the ecu and injectors in an effort to protect them from your stupidity.

the diode is still in the earth wire what do you think i should do

It must be shorted then. Just grab a 1N4004 diode from Jaycar or DSE and solder it in. Clicky Clicky (http://www.jaycar.com.au/productView.asp?ID=ZR1004&keywords=1n4001&form=KEYWORD)

thanks mate will give it a go