gfci's wont reset,fridge and living area light only work

all outlets dont work,bedroom has no power,no power in bathroom, living area and kitchen lights work but no other lights.theres a gfci in bathroom and kitchen both are tripped. i replaced both gfci's with green indicater lights showing if properly wired, both gfci's have lit green light.niether will reset.my little knowledge of gfci's tells me theres an open line or short somewhere in the wiring down the line of the gfi'c.first whats the best way to find where the short is,and second theres a box in the shore battery compartment that i believe is a inverter.how do you tell if its bad, and does it even matter since im hooked to shore power.last, how can i get a 120 wiring diagram so i can tell the sequence of outlets to help diagnose or possibly rewire.i changed all outlets inside and out of coach and fuse box and fuses.have a volt meter,but never used one.any help would be appreciated. thanks jess.