4 wheel drive not working properly

[sledandy]

Hey everyone so i was out driving around in this new snow today and discovered that my 4 hi and 4 lo don't work. The dash buttons light up showing like the 4 wheel drive is engaged but it isn't because i was stuck and only a rear wheel would spin and i could never feel it 'clunk' in. However when i put it into auto 4wd, it locked right into 4wd with out even any wheel slippage.

So does anyone have any ideas on what this could be?? The 4x4 actuator was replaced about 3-4 months ago if that means anything. I'm hoping this might be something simple like electrical or some kind of sensor or something. I wouldnt think it would be the transfer case becasue when i put it in auto the 4 wheel drive works fine, i just don't have 4 hi or 4 lo. So if anybody has any suggestions please let me know, thanks.

By the way its a 1999 chevy silverado ext cab z71 5.3L with 173,000 miles on it.

[Jeremy airjer W]

Welcome to FM Sledandy!

I'm kinda wondering if the shaft in the transfer case might be binding but then the lights shouldn't illuminate on the dash?

There should be a few ideas for you as morning roles around!

[fishon68]

If this has the dash button switch, i would check that?