So instead of just waiting for an answer. I installed a high output alternator on my car. 2011 mustang with a sound system. alternator is from Powermaster. One youtube video from a retailer showed it a simple swap and using all the stock wiring. Dumb me knowing about the Big 3 thought it would be ok temporarily installing it. Now i am getting battery and check engine lights. I know. dumb me. So i researched this many months ago where all the wires go but i could never figure out where the engine ground is. I have an idea but nothing for sure. Please believe i have looked. I just dont know. I am taking the alternator off in the morning because i dont want to mess up this car. Any help PLEASE!!!!!!