92 Jetta 1.8

Hey guys i hope someone can help me.
my 92 jetta wont start sometimes. i replaced battery, alternator, coil, wires plugs, distributor, and starter. I can push start it with no problem, and i get power to all of car, when i turn on key the fan comes on but i get nothing from car trying to start. no clicking, nothing trying to turn over. Its driving me nut, ive even rewired the whole underdash cuz i found some melted wires. please someone help me

Try replacing the ignition switch. Just my thoughts.
Franco