starting issues

Some of you guys need to review your terminology. The "solenoid" is on the starter, and you don't ground anything on it. The starter RELAY is on the firewall and that is where I'd start

You have two small "push on" flag terminals. One gets grounded through the neutral safety switch in neutral or park. You can follow it down the firewall to the transmission. The remaining one, usually yellow, is hot when the key is twisted to start and fires the relay when the other flag is grounded

Check for voltage on the start wire, and check for voltage on the neutral switch terminal. This is with the key in "start"

You SHOULD have voltage on the one from the key and should have nearly ZERO on the one going to the transmission/ neutral switch

AND WHAT YEAR MODEL IS YOUR CAR!!!!!