Hi Bob and Suzanne,
Thanks for the info. I just answered Bill that I found the fuse in the engine compartment. "eau mer" was out. I pushed in 'in' and switching it on the light of the chain washing pump went on for a second or 4 and then the fuse came out again.
So may be it is possible that the pump is frozen by salt deposits as you suggested. Do I have to remove the casing of the pump before I can reach the vent blades?
So I have to find the pump. I will check the manual.