Ok so I had my truck in the shop to have the 4th trans installed. Go and get it not 7 miles later it dies! Tow it back cuz it ran beautiful before trans was done. Guy checked battery's one no good. So buy a new one she started and runs again I go 15 miles this time and again it died!! Towed it home guy said probably alternator. Charged battery still no start! Could it be auxillary battery dead? Please please help!!!!!