I thawed out the pipes at my modular, but still no water, how do I diagnose that it is my well pump?

Is your pump above ground or submersible (in the well)? If above ground, then the motor should run once you know the pump is thawed out (assuming it froze... absolutely not a good thing). The motor is not affected by cold weather, but the pump itself is. Of course, be sure the breaker is on.