Check the ground underneath to make certain you don't have a leak somewhere. When I de-winterized this Spring my pump kept coming on every few seconds. I checked and found that one of the hoses going to the sink in my outdoor kitchen had worked loose a little and was leaking. I tightened the connection and the leak stopped.
2013 Silverado 2500HD LTZ CC 6.6L Duramax Diesel
2014 Sunset Trail SF270BH
Holly & Buster, mini Dachshunds
2016: 1 trip, 3 nights in 1 state, 316 miles
2015: 5 trips, 18 nights in 3 states, 2707 miles
2014: 5 trips, 14 nights in 3 states, 2426 miles