Most likely there is a solid state 'relay' in the module. i.e. - Transistor switched power source. There may be a real relay too for all I know. What you could do to protect the module is use the existing feed to the OEM pump to switch a relay for the fans and the pump and run your own hot circuit. That would probably be my first choice as it would allow you to fuse the circuit as you see fit and keep the OEM module from over amping.

Cheers!