OK, place one test lead on one fuse (transformer side of fuse) and the other lead on the other fuse (Tx side of fuse again). If you get no voltage reading, you have no secondary AC supply.
Well, I did that, if you mean the fuses
inside the battery charger
(The AC panel on the boat have breakers)
Well, I did check the AC output by measuring for any kind of current on the AC circuit by removing the AC fuses and inserting the mulit-meter probes in the "female" side of the fuse holders.
have juice going in to the box, as the fan is running at all times.
It has some stray current
going out as I can measure 0.7 to 1.5 volts fluctuating.
Somewhere inside the box the current gets lost
and the fuses ain't the problem.