Clean AC strainers on CAT 5 - STB SIDE

close sea water valve

open the lid of the long metallic filter housing

remove filter element, clean it , making sure every hole in it is clear from dirt and debris

clean the lid

re set the filter element inside the housing .

Make sure you have the o-ring . close the lid clockwise , don't close it too tight. just enough to avoid leaks

open the sea water valve. verify no leaks.

Turn on the A/C and verify normal seawater flow.