4 Wheel Drive out-- now what?

[Guest]

I have a 97 4x4 5.4L The all wheel drive has never worked and 4 low sometimes since I bought it 5 years ago. Now only 2 high. When I turn the switch on the dash to A4WD the light under the tach just flashes on and off--"A4WD". Up to last week when I turned the switch one click further, the 4High light would come on and go into 4 wheel drive, no problem. Now the A4WD still flashes but when I go to 4High there is a clicking sound under the dash like a relay for about 5 to 8 seconds then nothing, no light, no 4 wheel drive, nothing. It stays in 2H. I removed the switch on the dash and cleaned it. Still the same. What can the problem be and what can I do? (I have ordered a new switch.)