Switched 12v ignition source needed

Ok i need a switched 12v ignition source for my nitrous system. I spliced into one that had 12v when the key was on and 0v when the key was off. Then when i armed the system my windshield washer pumped kicked on. So whenever i arm it the windshield gets sprayed. Nice little surprise i got. I spliced in and made a Y connection with a butt splice splice with 2 wires in one end and one on the other. from the butt splice it goes Y's out again into 3 switches. Heater, Arm, and Purge. Can anyone give me a hint on whats goin on and a suggestion for a switched 12v power source. Thanks much.

Im still gonna use a toggle switch but i need a wire to splice into to get 12v when the key is on. I think the windshield washer pump is turning on because im providing a ground every time i turn the switch on. Its one of those light up toggle switches that requires a ground wire to turn on the light. Im gonna try disconnecting that ground wire from the switch and see what happens. But if that doesnt work i dont know what to do and im gonna be afraid to tap into any other wires for fear of turning on something else along with the nitrous. I might just keep it simple and take the power wire for the cigarette lighter and use that. I actually made a lighter that would turn on the nitrous system when you pushed it in but wouldnt heat up the coil. I forgot where i put it but it was pretty sweet, just got bored at work one day and when you work at a parts store u have everything you need. If anybody is interested i might try and make another one and post a write up. It took me a while to figure it out and make it work right.

Thanks Urban Ill prolly look into that when i get home. But since those lighted switches provide a ground im still in fear of turning something else on at the same time so ill prolly just steal the power wire from the cigarette lighter or just remove the ground wires on the switches if that cures the windshield washer problem.