First off, Welcome to the site.
I would start by checking all the electrical connections for corrosion, bad connections. Etc. You can also disconnectthe hydro hoses at the ram and have someone move the switch up and down and see if the pump is moving fluid. Ram might be bad, hoses could be kinked, crap in the tank, etc. Has also been suggested to run a dedicated, fused power wire off the battery to the switch just for the pump.
Good luck! Very nice boat BTW