4X4 Low Range Light

[05 SD F250]

Does anyone one have any ideas as to why my 4x4 low range light doesn't come on when I'm in 4 low. When I put the truck in 4 high the light comes on and I'm in 4 wheel drive, then if I switch to 4 low it feel like the truck is in a lower gear but the low range light does not come on.

Thanks for the help.
I have a 2005 F250

[smokersteve]

Going into 4x4low, the trans should be in neutral and you should be stoped. If the light does not turn on, role a little bit.

If you are in 4x4low you will notice it the second you start to give it gas.

You may have a bad fuse if the system does FULLY engage with out the light.

You should also be able to hear the electric motor(eng off) engaging 4x4 high and 4x4 low on the transfercase.

[05 SD F250]

It's not the fuse because the low range light comes on when I start the truck