Your battery voltage may be low. The lift motor gets ALL its power from the battery and it takes a healthy battery to raise the top, but very little power to lower it. The clicking you hear is probably the solenoid switch turning on, but if there isn't enough power flowing through it, the motor won't run.
Plug the trailer into shore power overnight. If your converter is working, that should charge the battery enough to get the top back up. If not, do you have the manual lift system (optional) in your trailer? If so, just put the manual handle into the receiver on the pump and move it back and forth. The top will go up slowly as you do this.
Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH
2014 F150 Platinum 4x4 3.5L EcoBoost SCrew