Bose unit turns on and off while driving
 

I have a 93 vert. I have been trouble shooting the on and off power to the Bose system. The power does not go completely off because the cd starts back where it left off. Another quirk is the radio will not come on when I do not hear tone generator that tells you the keys are in the ignition. Bumps in the road causes it to turn off as well. I took the covervpanel from underneath the dash and problem seems to better. Any help in diagnosing this problem would appreciated.
93 cruiser