I'd suspect the circuit breaker is tripping for some reason, that's the click you hear and cause for the delay.
One of two things, either you have a faulty circuit breaker (too small, or opening too early) or your pump motor is drawing too much current.
But it's not normal, so I'd take it to the dealer before it just quits.
Now-2014 Sierra 346RETS 5er BUB
Then-2002 Keystone Springdale 286RLDS TT
Nights camped in 2014-28, 2015-127, 2016-10