Starter Solenoid keeps spinning
 

I recently put a new engine in my 93 fd and now when I turn the key to acc the starter solenoid keeps spinning. Anyone know why or what to look for? Also, I have a female plug with 4 wires coming from the driver's side firewall and I don't know where it goes. It's the same size plug as the male connector for the ignition coil harness. Any input would be much appreciated.

Well, if it is bolted correctly onto the transmission and it kept spinning, you need a starter.

-AzEKnightz

I thought it was the solenoid. So I replaced both the starter and solenoid. Still spins.

Is your car an auto? If so did you put the flex plate on backwards? A new starter should be kicking it's internal gear out so it engages the flywheel teeth. By the way, the solenoids on a starter don't spin. They only send power to the motor.

No its a manual. So, what could make the starter spin by just turning the key to acc? This is a new starter I put on and it's doing the same thing my old one did.