Crank No Start

So at the beginning of this summer my truck would turn over and idle but eventually die out, we suspected it was something to do with the timing to we changed the timing assembly an attempted to crank it again only this time it would crank but not start. We checked the usual faults however we were not getting any spark at all, no throttle body movement when gas pedal was pressed when cranking over, we changed the spark plugs, coils, throttle body is cleaned, we are now suspecting it to be a electrical problem. We swapped out the ECM with the fog light relay however that did not change anything at all and kept doing the same thing. We are at a standstill on what the problem is and are lost of where to go from here.