Well,
I cannot speak for other manufacturers but, Winne and Itasca have a complete set of "Trailer fuses" in a totally separate location, far, far away from the front of the coach. In ours, an '04 Itasca Horizon 36GD with the C0-7 330HP CAT, those fuses are located behind the last panel, (louvered one)that a couple of screws are needed to be removed to raise that panel.
On the some other Itascas and Winnes, that trailer fuse block is located in the electrical (shore power) compartment, behind a removable panel. So, if you have one, I'd begin by looking around in all those rear compartments, tucked up in corner, maybe even behind the rear cap in a corner some place etc. I'd bet you have one for sure, just not sure where.