I went to the boat today to examine the circuits in the enclosure behind the dash. As you found there is no fuse in the dash fuse block assigned to the fan circuit. There is a 30 A fuse assigned to the sub panel. The “Ranger Tug R27 Accessories 1” electrical schematic for our vintage of R27s shows a lead from the sub panel to a 10A breaker and on to the fan motors. The sub panel lead is bundled together with a number of other leads. One would have to open the bundle to trace where this lead goes. I have not done that. Now what is a sub panel? I got no answer to that question. It seems to me that there is a parallel series of connections to the to the input terminals of the dash mounted switch breakers.
Going forward I would use a voltmeter to check for voltage first at the fan breaker’s input and output terminals. If voltage here, then at the switch’s input and output terminals (switch turmed on). I believe that the bottom right (viewed from the back) terminal is the output and the terminal above is the input from the breaker. If these are all good, then checking the fan connections will need to follow.
As to you last question regarding an inline fuse, I can see no evidence of one.
