electrical

Just bought a 95 sonoma extra cab, 2.2 engine. Nice......or so I thought. Headlights only come on when e-brake is disengaged. No high beams, no lights on the instrument cluster, no horn, no liscense plate lights. Are these problems Connected? Looks like the cd player was recently installed as several different colored wire jacket under floor mat on passenge side floor. Could be related? Any help would be greatly appreciated. Thanks