[sierra99]

My 99 silverado lt has done the same thing....I read all of the post about the transfer actuator but I looked at the switch itself. Pull the switch and take it apart. Look closely at the solder joints in the back of the switch while pushing on any and all of the buttons. Mine had a hairline crack in the solder joint. I had the same symptoms. Now you can either replace the switch or get a soldering iron out and add/ resolder all of the joints. I resoldered all of my joints. Now all is working great. Try that..