i just brought it 2weeks ago brand new....... and it was working great....then i took it out....then i put it back in again..then it wont turn on..i put all the wires together...and do i have to screw the ground wires to a screw or just touch it on the metal? or does it matter? i check the fuse they are fine......any help will be great....

 

it doesn't have to be screw on to the metal, if you are just testing to see if it works.

Have you check the fuse that came with the deck and also the fuse under the hood.

you should check to see if you have power first then try to connect the radio