Complex sentence: When he takes control of the car and stops, she jumps out and tries to signal a passing car to stop, he uses the fan belt pulley of her car's generator to break his handcuffs apart, causing the car to overheat and break down.
Split into simpler sentences: When he takes control of the car and stops, she jumps out and tries to signal a passing car to stop. He uses the fan belt pulley of her car's generator to break his handcuffs apart, causing the car to overheat and break down.