1990 Caravan Will not start

My 1990 Caravan will not start. I have shorted the starter terminals and the starter turns. I have replace the ignition module and no luck. The starter will not turn. I am not getting power to the starter solenoid. I have replaced the ignition relays (2). All interior and exterior lights work. Just no power to starter. Their is 12 volts on the hot side of the starter but nothing on the solenoid side (black wire connected to starter). What's next ---- the ECM?

I would check your neutral safety switch. I think it's on the transmission where the gear selection level is.