new cd player just installed now engine won't turn over

I just installed a new cd player in my 99 grand prix gt last weekend. It has worked great. However one morning 2-3 days later my car wouldn't start. I had no dome lights, noo dash lights, or anything. However the battery had power because the jumper cables sparked when touched together and connected to only my battery. I unhooked the battery cable for a couple hours and reconnected it. Then it started. Now a day later it won't start again. I unhooked the cable to the battery for a half hour and it still won't start after reconnecting it.

Could there be a problem with a short with the CD player installation? I thought I had it done correctly. Or is there something wrong with the compatibility between the Cd player and the anti-theft on my car?

I'm just not sure.

Even if the battery is "dead' it will still spark. It just might not have the juice to turn over. You probably wired the HU wrong and it was drawing power continually even when the car was off.

Actually there is enough amperage in the battery because after sitting overnight with the battery cable un hooked, after I reconnected the cable this morning, the car started. What doesn't make sense is sometimes after I come back to my car to start it there is no power to the dome lights dash or anything even after my remote entry works, then the engine won't turn over. Then after disconnecting the battery for more than a couple hours and trying the car again it might work.

All the wires in the back of the CD player are accounted for, and I used a wiring harness. There are no loose wires there to short out.

Any other thoughts?