The clicking sound you hear is the power relay.
This situation only occurs during the peaking portion of the newer style battery tender, this occurs when the battery reaches a certain voltage, like 13.2 and then increases and decreases the voltage for a while then it stops.
I have never just left it on there to see how many times the fuel pump will cycle it may only happen a couple of times. Maybe just hook it up and monitor it for a bit and see what happens?
