The pilots lost aileron control shortly after takeoff while in a left turn. The left turning tendencies of the aircraft could not be corrected and the aircraft crash landed in the Caribbean Sea. Post crash inspection of the aircraft revealed the left aileron control cable was trapped within a bundle of electrical wires and cables. This occurred when an electrical cable from a reverse current relay in the right wing to the main junction box in the left cabin area at the center wing was changed and secured. The aileron cable chafed through the protective cover of the large electrical cable. When contact was made with the metal electrical cable the aileron cable arched at several points and separated at two different points causing a loss of aileron control. PROBABLE CAUSES: electrical system,electric wiring..incorrect aircraft handling..not possible..pilot in command maintenance,service of aircraft/equipment..improper..company maintenance personnel electrical system,electric wiring..chafed electrical system,electric wiring..arcing flt control syst,aileron control..separation flt control syst,aileron control..loss,total