GM-GMC: 89 gmc electrical problems, gmc vandura, lighting circuits

Question
own a 89 gmc vandura and last night i was coming come and was getting dark so i went to turn the lights on and the car shut of. so i pushed switch back in and re started fine. today mourning i go to start and i have no power the service engine/check engine light does not come on. the starter cranks, but no spark and no fuel. checked connections at battery and starter they are tight am i looking at a bad ground? or wire shorted to another? did it take out the ecm? any help is appreciated

Answer
its hard to say without further diag. all of those are verry possible. i would also look at fuses and check connections and wiring in the lighting circuits as well as chafed wires but make sure to solve the problem with the lights before replacing the fuses as u may just waiste a fuse.