No Power on new receiver install

I have installed a pioneer stereo in my Nissan and I used an adapter to make the install easier. I have the wires connected but I have no power to the receiver. I really have no idea how to trouble shoot or solve the problem, any help would be great.

Thanks

You connected the power, ground, and switched power all correctly right?

If you were doing the install with the battery connected you might have touched the power wire to ground and blown a fuse. If you have a volt meter you should take out the receiver and check the power and switched power with the ground to make sure power is actually getting to the receiver