Re-Edit. Have a FAST XFI setup and am experiencing severe voltage drop. I'm reading 14.2 volts at the alternator, 13.8 at the battery in trunk. When everything is on, I get 10.5 volts from my laptop. I've already been through 1 battery and 1 alternator and the car only has 350 miles on it. It's a 140amp alternator and Powermaster says it'll work for my car. I've got 4 grounds and am still getting voltage drop. Is there a key element from the FAST harness I'm missing?