Won't start has power, has pull back light switch start. Lights come on when off

ASSUMING the 'aftermarket' anti-theft is working properly (when you pull back/flash-to-pass on the light switch), then you need a second person to help test power to the starter solenoid and back, in the starter circuit, until the source of problem is located. IF proper power to BOTH STARTER MAIN LUG AND SOLENOID(WHEN KEY IN 'CRANK' POSITION), then i would suspect a failed starter. That also, can be 'bench tested'. Good luck.