wanderring sierra pls. help!!!

Hey people!
I own a 2003 sierra whit a serrious problem whit the steering. It wanders for no reason and light cross winds just make a nice little drive (awfull)! Any bumps or dips...road crown will affect it in constent over steering. I had numberous enlignements,front end checked, gueer box changed, caster was played whit to enhance the feel of the steering gm just cant figure it out. this truck is litteraly (driving) me crazy. If anyone could help I'd surely appreciate it alot!
my e-mail add. is: [email protected]
Thanks,

Try checking your idler arm. I have a 1990 and have to change it once a year. But my truck spends half the time in the woods. Don't know if that makes a differance.

check your pittman arm to see if its loose and check the idler arm for excess play. does you truck have a dampner for bump steer? if so it may be shot.