thanks for the replies
the fuse on the stereo is fine, as is the one in the car. There seem to be three cables available from the car (excluding speakers)
red, 12v (assuming this is iginition) and brown (assuming neutral) and a 1.5v supply as well (yellow)
I have wired the red cable from the stereo (labelled ign +12v) and the black cable in, but can't see anything else that i can connect. I have checked the power, with the ignition off i am getting 0v, but on position I and II i am getting 12v as i should be.
still