I have a 98 Expedition EB 5.4L 4x4 Expedition that is having problems shifting into 4 wheel drive. When I move the 4x4 selection ****, the various 4 wheel drive lights don't come on in the dash. I know the lights work, because they light up when I first start the engine. Also, I don't hear or feel anything happening underneath by the transfer case.

A few months ago, I was able to shift into A4WD, but not 4H or 4L. Now, I can't shift into any of them.

I had this problem about 18 months ago right after the transfer case was rebuilt. Since it had just been in to the mechanic I took it back under warranty. The mechanic told me that all it needed was to be "reprogrammed," and they had it working in short order.

Is there any truth to having to "program" the 4 wheel drive? If so, how do I do this? Any other thoughts on what the problem might be and how I can diagnose/fix it?

Thanks in advance. I sure would like to have my 4 wheel drive back before the snow gets much deeper.

 

It's more likely that he reused the shift motor when he rebuilt the TC. Your whole problem sounds like a new shift motor will fix you right up.

 

Thanks. Is there a good way to test the shift motor? I would hate to replace it and have it not be the problem.

 

I don't know the pin-outs off hand, but I'm sure if you got under there you could see which wires go to the motor and probe those for power. Here's a write-up done for an Explorer, the Expedition is similar. This should give you a general idea of what to look for.
4X4 Shift Motor Rebuild - Ford Explorer Ranger Enthusiasts "Serious Explorations"®