On my way home from work yesterday, I noticed my check 4x4 light was on. I then noticed that my switch was turned onto 4x4 low. I cant say how it happened but I know it wasnt actually in low because I was driving at higher speeds. It did not feel like it was in 4wd either. Now if i try to engage 4wd it does not seem to work. Have I ruined my 4wd?

 

Try putting the truck in neutral and putting it in to 4wd. If it still doesn't work you can go to the transfer case and theres a pin of some sort on the 4wd actuator motor that you can tap with a hammer to engage.