To see if they installed a ground cable from the battery back to the alternator area in the engine just look at the battery and see if the black ground cable is bolted to the chassis near the battery or disappears under the rug heading for the engine. If it's bolted to the chassis, then the chassis carries the return current which spreads out as it travels back to the alternator resulting in a stronger electromagnetic field. I installed a return cable under the rug on my 2002.