Electrical short in 05 6.0 need help

[chf8500]

Put a new alt in last week, old one fried and tech says not uncommon on these motors around 100 K , new 850 cc batts in the last couple of months also. problem, last day or so alt lite in dash intermitanly off and on at 1800/2000 RPM, checked with tech, new alt, bigger, don't know if problem was prior or it just started but I found a parasitic drain, 12V test lite between batt and grnd cable, pulled all the fuses under dash and in engine compartment, lite still on. No accessorys on truck and pure stock except for pioneer radio. Any one have any ideas about locating this short or does Ford have diagnostics to find it, local dealer said good luck but he is also pretty small time as far as equip.