constant running pump!

[rpw]

I am having problems with my system 1s kit.I have everthing connected right,red wire to battery positive,black wire to battery negative and purple wire to the coil and the wires connected to the pressure switch.my problem is when I turn the ignition on,the pump won't stop,I have even joined the two switch wires together but the pump still runs.can anyone tell me what is up and how I can solve it?thanks