4 Wheel Drive/SUVs: Blazer jumps into 4-wheel-drive, front wheel bearings, dashboard switch

Question
Hi Carl,
I have a 1999 Chevrolet Blzaer ls, 6-cyc, four-wheel drive automatic, 107,000 miles, well maintained. Lately, the Blazer has been jumping into 4-wheel drive on its own. The lights on the dashboard switch flash and if I'm driving at road speed it goes into 4-hi and if I'm going slow or stop while the lights are flashing, it goes into 4 low. Swiches out easily when the 2-hi button is pushed. No pattern to it. Recently had front wheel bearings replaced. This happened a few years back when the bearings went bad the first time. (They've gone bad twice now, but that's another story) I know the wheel bearings should have nothing to do with it but I have to wonder. Thanks for any ideas you or anyone else might have on this probelm.

Answer
Rodney,

Sounds like your 4-wheel drive switch, or wiring is shorting out.  Check out the switches, and wiring.  If you have a fuse to this circuit, pull it and see if you still have the problem.  Other than that, make sure you have a good ground going to the transfer case.  Actually, going into 4-wheel drive on pavement or hard surfaces is extremely hard on the drive train, so this needs to be repaired asap.

Carl