Why won`t my car stereo come on?

I added some new speakers and e thing work fine until i tried to put the deck back into it`s position.it will load and eject cds and then go back off. when i press then display it will flash the time for one or two seconds and then it goes back off. i tried it in another car and it worked well. i tried another stereo in my car and it did not come on. so i know the problem is in my car`s wiring.is there any wiring advise for me ? thanks fin.
Answer
Does the system have an anti-theft device?