Hose clamps do not work well with PEX (personal experience). PEX is too hard. I stripped alligator clamps trying to keep PEX from leaking.
As to the blown fuse. unplug the pump and make sure that the fuse does not blow with the pump out of the circuit. Not knowing the age of your pump, I can't recommend the next steps.
John W. Irwin
2005 Classic 28 "Sabre-Dog III"
2013 Silverado 2500HD Duramax/Allison LTZ
WBCCI #9632, TAC TX-10