4wd light on dash is on but 4wd still works any advice? Thanks.

 

The 4wd light on the dash is supposed to be on when (and only when) 4wd is working.

Did you mean to ask that question the other way around? That light is controlled by a switch on the ADD; if there is a problem I'd start looking there.

 

The light has been on since getting the truck this past February I will dig up what I can on the switch you sent me, thanks scope.

 

Most likely problem is that you have a vacuum hose disconnect that is leaving the ADD in the engaged state all the time. Thus the light is always lit. Shifting the transfer case out of 4WD still disengages the front drive shaft, so the vehicle operates in 2WD, but you're still turning the front drive shaft and differential.

Park the vehicle with the engine off and the transfer case in 2WD. Reach under it and try to turn the front drive shaft between the transfer case and the differential. If the ADD is disengaged, you will be able to turn it. If the ADD is stuck engaged, you won't.