Nitrous Oxide - NOS Wiring HELP

So I am trying to hook up my NOS kit...I have 2 relays...one for my stand alone fuel system and one for the NOS.....I have everything wired up like it shoes in a skematic that I got off of here, and had one of the local speed shops modify it to put in the other relay for the fuel pump.....now the question I have it I am using a push button activation switch to turn the NOS on and off....not a window switch and I also have an arming switch aswell.....well the arming switch runs off of a "turn key 12v power supply" an accesories and a ground wire......what the hell do you hook the 12v turn key wire to......I have a fuel pressure guage that I tried to just tap it into and it then caused the fuel pressure guage to not work......I thought I blew a fuse somewhere but I didn't....I proceeded to rip open the dash and just fiddle around with wires, unhooked the wire that I had spliced in to the fuel pressure wire and then I started the car back up and the fuel guage now works....wtf is going on? And where can I hook the arming 12v wire to? PLEASE HELP I NEED THIS DONE TONIGHT!!!! Thanks

Well this is a problem. The hot or input toggle wire should be connected to any 12 keyed power supply. Take your test light and in the fuse box area there usually is an open hole that has power on it, when the key is on. OR
you can splice into the radio hot wire. NOW this only applys
IF
your system is wired with relays controlling the main power to the noid (s).
Can you show us which schamtic you choose to use for your wireing, that will be a huge helper.

Ricky