My 02 WRX will crank over but will not start. Story goes as follows, the previous owner was installing a stereo system with the battery connected while doing this somehow something shorted out and now the the car will crank over but wont start. It has Spark and is getting fuel per dealership, so I'm assuming that it is electrical? Is there anything I should check? Any help would be greatly appreciated..... Also the car ran perfect before them trying to install the speakers in the rear.