follow the power trail back to the battery and see if it's broken anywhere
you never know it might be one of the fuseable links gone from the battery or the fusebox itself thats playing up

the wires you want are going to be either black with a blue track of black with a yellow trace

silly i know, but have you actually connected the switch to the key? if you are loking for a feed when you turn the switch but there's nothing turning....................................