Originally Posted by bligh
The Op stated that carver made many more gas models than diesel models of his boat. His model was a diesel factory conversion. The fans must be leftover from the gas model buildout and dont serve any purpose.
The blowers are intended to provide air and cooling to the ER. I have a rather small ER and the blowers provide lots of air. They will suck the air conditioning right out of the boat if turned on with the AC running.
If I remember correctly the USPS boating course manual suggests operating the blowers on a gas boat several minutes BEFORE engine start. So activating the blowers via the ignition switch would not evacuate gas fumes from the bilge before engine start and is probably why only the diesel powered version of my boat has this feature ie: blowers connected to ignition switch.
Since I can remember to manually turn on the blowers when I operate the engines and genny I will probably not install fuses in the power feed. If they blow again I would not hear the blowers (or lack of) above the engine noise and they would be left off.