Well last night I dug a little deeper and found two wires, one from the switch disconnected and wire nutted off. I connected the wires, turned on the switch and instantly blew a 20amp fuse in the power distribution box. One of the wires runs into a closed off area under the fridge so I will have to do some disassembly to see where it goes. I looked under the trailer and found no pump or extra wires running to either of the holding tanks. Only level sensor wires. Ran out of daylight so maybe a little more investigation today.