@kozza just a couple of questions that may help get you an answer.....
1. Has your cars plug been wired up to have constant power?
2. If it has been did you have constant power to it with and without the ignition on?
Reasons I ask:
1. Pin 2 is reserved as the pin for reverse wiring and most Aussie cars are not set up to for it so the pin is left unpowered.
2. If it has been wired for constant power then you would likely have an issue with fuse, loose connection, broken wire, faulty solenoid (If fitted) etc.