Ok couple weeks ago I had ford install a new alternator in my system to fix the short, they said it was an internal short. Well 2 weeks later, I was idling and my voltage dropped for half a second and I could hear the fuel pump almost turn off then back on. It did this twice so far within 5 mins of each other. Otherwise it drove 10 miles back home fine. What should I do? brand new alternator and less than yr old battery.