No voltage coming from back of dash

I wanted to put a neon in the back of my truck so I cut the wire so i could extend the neon and add more wire. My neon is hooked up with LED's inside my air vents. There is an inline switch for the LED's and neon. My power source and ground source for the LED's and neon is from the back of my headunit. I had the switch turned on and i touched the positive wire and negative wire on the neon together and the LED's and the neon shut off. I hooked up the neon back together properly and the neon didnt turn on. neither would the LED's when i toggled the switch on and off. I started my car and the head unit doesnt turn on. I checked the fuse box and pulled out every fuse and all of them were fine. I disconnected the yellow wire from behind my head unit and checked the voltage when the car was on and there was no voltage coming from the yellow wire. I am very confused right now. If anyone can help me out that would be awesome, Thankyou.  03 F150 on 24's

HU:Pioneer DVD5700

Frt:MC57

Subs:(12)S12L7

Amps:(3)KX2500.1's, MC-2004

There's nothing to be confused about- you touched the positive and negative wires together, creating a short and blowing a fuse.  You'll have to look again for it's location- check your owner's manual.  If it's not in the passenger compartment, look under the hood- and use a meter to check it as well as a visual inspection.My ex once told me I have a perfect face for radio.