I had the same problem with mine and it ened up bieng a fuse wasnt tight in its holder on the power cable going to the fuse box.
2002 red GT mustang
GO:Flows, BBK lowering springs, KYB struts & shocks, Mac straightshot CAI, SCT chip and tune, Accufab Plenum 70mm, Motive 4.10's
Show:18x10 & 18x9 Bullitt Deep Dish Chrome Wheel's
295/35/18 & 265/35/18 Michelin Pilot Sport PS2's
tinted windows, billet grill