okay this wat happened my car sat for about a month,(i doubt that has anything to do w./ it), i took the battery out and put it into my maxima because i sold it and it needed the battery, and i bought a battery a few days ago, and my friend decided he would go ahead and put it in while i was in my house, and he hooked it up backwards. and he told me when he went to put the negative on it, it sparked. but he still hooked it up, he checked the lights and they turned on so he thought it was right, so then he tried to start it up and nothing happened. i noticed, now that the battery is connected correctly, that the headlights don't pop up now, and my volt meter doesn't move either. and the car doesn't try to start at at all. i checked the fuses and they all looked good, so i'm worried that he may have fried my wiring harness
could someone please help me in determining if that is what happend or if it could be somtehing else???