Please Help! Proform 680?

I have a proform 680 treadmill. When I press start, it will run for about 2 seconds then stop. The console and incline work just fine. When the treadmill stops, the screen goes blank then the screen turns back on again by itself. Also, when I press start, the lights in my house dim drastically.

I unhooked the black wire and red wire from the motor and hooked them to an 18 volt battery. The motor ran just fine and didnt stop at all so it isn't the motor. Any other suggestions?