Ok when i go to turn on my 4WD high or low it does not come on but if i leave it in 4wd high and turn the truck off come in a hour or two it turn it on but it still not in 4wd drive now its say 4wd high is on but when i try to switch it in 4 low it does want to switch but when i switch it in 2wd it will switch Please help and for some reason my 4WD high and low are flashing on my dash with i turn my truck on please help need info.