I have power to the starter solenoid when I turn the ignition switch to start but it will not engage the solenoid. I can jump the S terminal to the battery and it turns over. I installed a new starter switch and I still can't get the solenoid to engage. There has to be a reason. I'm stumped. I may pull the wiring harness off my other car and see if that is the problem. The car has started in the past. I have a small block 350 in the car and the under hood wiring harness is 6 cyl. I have 12.7 volts to the S terminal. Any ideas?