Engine cranks with the key in the run position PLEASE HELP!!!

[67Coupe5.0]

I am hoping someone has had this similar problem and can help. I just put a 5 liter out of a 87 in my 67. The problem I am having is now the motor wants to crank over with the key in the RUN position. I am using the 67 wiring for the starting circuit. Any ideas, it did not do this 2 months ago before i did the motor swap. So i must be missing something easy that may of happened during the reassembly.

 

[pabear89]

On your sol, move the brown wire to the I position and it will not crank with the key on.

 

[Wicked65]

Starter solenoid wires are reversed... Tried to run over myself one day that way..

 

[Wicked65]

or solenoid is broken.

 

[S-Car-Go]

This could be tied to which type of starter you used. The new mini/hi torque starters from 5.0s are wired different than the old 67 starters. The new ones have a solenoid on the starter.
If you used the old style starter, remove the S & I wires from the sol and check for voltage in run and start key positions. If they are reversed, swap them. If they are correct, replace the solenoid.