94 k2500 wheel speed sensor

I have a '94 K2500 w/ a 6.5 turbo that I've had since 1995 and yesterday the speedometer, tach were doing very strange things. Also a couple of times the transmission seemed to shift to neutral and engine went to 3500 until I shut it off while driving on the hiway. Also the dash brake lite came on and it acted like the power brakes didn't work.

What's up with this? My brother seems to think it may be the wheel speed sensor. Can this sensor cause all these problems, if so where is it located?

A wheel speed sensor will NOT cause your problem.
Check your alternator and make sure its working. Check your battery cables and ALL battery and engine grounds!!