CD Player Not working...

Put in a brand new kenwood cd/mp3 player in my 98 dodge ram 1500 laramie. The player worked fine until 3 nights after installing and i had to turn on the headlights. It turned off and when I got home and turned off the lights it turned back on. Now the am/fm doesnt work but everything else does. I've tried rewiring the harness but it will only work the way I already had it. Any ideas?