My 4 wheel drive on my explorer sport 2001 doesn't work?

When I turn the switch to 4x4 high or low nothing happens. The manual tells me to check the transfer shift module but it doesn't specify where it is. I tryed to look up a picture of it on the Internet but nothing shows for this vehicle. Can anyone tell me the location of this device or another part that I can check that will cause my 4 wheel drive not to work?|||Some vehciles have a "switch" in the center of the wheel in the middle of the hubcap,


it like the manual switch,


im not sure about newer vehicles but on some old ones it had it and you had to switch it over|||yes it will be your 4 wheel drive module check for 2 battery power orange, and green 1 ign power red and white and 2 grounds black and black and white if you have them replace module it is behind right side kick panel will have a 4x4cm on sticker only module there|||could be just a bad selector switch on your dash, or even fuse/relay since the operation is all electronic.