AQ 225D starter won't engage.

[elimontfort]

So I've been trying to figure this out. I am getting 12 Volts to my ignition switch. When I hit the key I'm getting 12 volts to the start side of the solenoid. And I have a good starter tried it in my truck. I also checked my grounds. But my starter refuses to start when I hit it with the key. It will start if If I use my bump starter and jump out the solenoid. Any ideas??