So my 4wd light stays on even when the truck is in 2wd. Its a 2006 silverado wt with the manual shift transfer case i put it in 4wd one day and it worked fine but when i shifted back to 2wd the light went out and then came right back on i can spin the rear wheels on loose gravel so i know its in 2wd but the light stays on any help would be appreciated