96impalaustin

im helping my dad work on his 1973 mustang mach 1 fastback with a 1971 429 cobra jet big block in it. my problem is when i turn the key to the on position the soleniod on the side wall makes a loud click. when i have the starter solenoid wires hooked up the the solenoid on the side wall the motor turns over still in the on position.. Please sombody help me get this motor to turn over by the key in the crank position...???