Ground wire/ car stereo/ cd player installation

I was wondering if anyone knew what would happen if one was to connect the 12 volt (yellow/orange) constant and switch wires before connecting the (black) ground wire when installing a cd player unit. Because the unit worked temporarily and quit after a few sparks.

Also I was wondering if the reason it will not work is perhaps because the wires have not been fully connected with splice connectors yet. I would appreciate any help. Thanks.

If you hook up those wires before the ground and u get sparks you more than likely fried the radio. Always hook up ground wire first. There is also wire harnesses you can buy that make the whole process much easier.