Trailer Brake Controller

Hello all! I am brand new to this forum so be easy on me please.
 
Well I am a proud new owner of a 2008 Chevy Avalanche LTZ. I absolutly love my truck.
 
So today i bought a Hopkins Impulse Trailer Brake Controller. Only reason I bought this one is because my brother has it on his '06 trailblazer and my dad has it on his '01 suburban 2500 and so i guess its just tried and true. Any way, I set it up...mounted and everything, but I dont seem to get any power to the trailer brake controller. I have done a search on the site and people say it has to do with a simple connection under the hood. If this is true, assuming i did my wiring right, where would I find that important cable that gives me power to the controller?
 
 
If there is no connection under the hood what is the right connection?
 
I have on the controller a Red, Blue, White, and Black wire
On the Avalanche I have a Red w/black stripe, dk. Blue, lt. Blue, and White
 
What I connected was white to white,  blue to dark blue, black to red, and red to light blue.
 
Thanks everyone!

The red/black should have no power unless you connect it at the battery. Go to the engine conparment, look on the drivers side you will see the main fuse/relay box. Between the fuse box and fender you should see a red/black tape up take it out and connect it to the empty stud at the relay/fuse box. If you look by the brake line below where the master cylinder is you should find the other red/blk c that one also needs to be connected.

Thanks for the help charlie. I will set it up this weekend.