Hi mate

This is how I have wired my brakes, I have run a live one that comes on when the ignition is switched on, this is on my kit car so its up to you were you get your live from.
So as you look at the sensor there are five pins, you have a row of two and a row off three, when looking at it with the two pins on top the left hand side top pin run a wire to the relay and then run a live to the middle of the three pins, I have solderd mine on as I dont have a plug
So when I switch my ignition on the sensor senses low pressure and switches the live through the sensor and on to the relay this inturn switches the pump on. Once it pressurises the accumulator it will switch the pump of. Well it works on mine so good look
So looking at it left top pin of the two to relay and middle of three live.
I hope this helps and I hope you can understand what I have wrote, If you need any more help just give me a shout, if you need to talk to me I will give you my number.
Paul.