Accidently hit the 4H wheel drive button going into park. Got back in and it would not go back onto 2 wheel drive. Its the push buttom system, on the dash. Just hard some clicking, when trying to engage 2 Wheel Drive. any help would be appreciated. Thanks

I believe you have to be in neutral to switch back if it is in 4WD (Low). Look at the push buttons, there are little lines pointing to a label or something that says neutral. It's in the manual too if you've got one.

Update: Check this...
http://www.ehow.com/how_5313929_troubleshoot-chevy-blazer-wd.html

That link is for 1999 which is a different system than 1998, diagnostics are different.

What transfer case do you have? NV 233 3 button switch, (2 speed selectable) or NV 136 4 button switch, (Auto).

Sorry about the link. That switch is used on 1998-2005 Blazer's with 4WD and "auto". I was just thinking it may be a simple problem like not being in neutral. I learned that the hard way when I first bought my Blazer back in 99. If it's something other than that like the transfer case I have no idea.