Check all your grounds for corrosion. Take them off, clean surfaces and re-install. Use a voltage meter and check volts to battery and starter before and while trying to crank it over. Also check continuity between starter and ground while trying to crank it over. be careful not to touch anything metal to positive and ground at the same time. PS: 12volt car battery will not shock you. voltage at battery and starter is safe to touch...but once it goes through the coils beware...then it can shock you. If you touch metal to both positive and ground/negative at the same time it can and will spark and arc...like welding...it can burn you and can be very dangerous. please take necessary caution.