Stays on all the time, have checked all lines and tubing everthing seems fine. 4 wheel drive system mechanically seems fine, 2wd and 4wd works the way it is designed. I do have the 2 lo kit and it never has worked all that well but the light has worked properly, up til about a week ago not even in 4wd the light came on, and been on ever since. The 2 lo kit does not seem to work all the time when the switch is on, sometimes it works and sometimes it dont. Any ideas on what to check. Thanks for any replies.

 

After all the checks you have done I would suspect a defective switch. Have you tried disconnecting the wires at the switch? If the light goes off when you do that, well, then it is the switch. To verify, remove the switch and do a continuity check in the on and off position.