If it is clicking, the light sensor is working. You may have an open in the control module. There have been a couple of threads on repairing the module. It is basically a fancy relay activated when the photoresistor changes value. When the threshold in value happens, the relay trips, and the lights come on. If the circuit is broken between the relay and the light circuit, the lights do not come on when the relay trips. Since you hear the relay, it is working. The fact that your lights do not come on means that the electricty is not getting from the relay to the lights. There are no other parts between the module and the lights other than wire.