What would cause the 4 wheel drive light to stay on in 2 wheel drive but go out when in either 4 hi or 4 lo? The 4 wheel drive works fine in both hi and low but the light works backwards.

 

Sounds like the sending unit on the T-case is to blame here. It is on the top of the transfer case on the right side. Not very easy to get to while its in the truck. You may have to remove the cross member and lower the trans to give you clearance. Just be careful not to lower it too far that the rear valve cover hits the firewall.

 

I was thinking it's probably the switch. I just wanted to know if anyone else has experienced this. I replaced it a few years ago when the light didn't work at all. It's weird that it's working backwards.

 

Mine was doing the exact same thing. Did it twice in fact. I replaced the switch in the transfer case twice as well, and both times the problem was cured... for about 6 months.

The 3rd time this happened was enough for me. I disconnected the wires from the switch and said the heck with it. To my way of thinking, if I can't figure out when it's in 4WD, then I need to start riding a bicycle instead!

chaikwa.