unless the panels were installed by the coach manufacturer, the rest almost all were custom installed. there are no certain design patterns that the installers could follow thus no way to know where those fuses are if there are any on the panels. i installed mine; i placed an inline fuse on the positive lead on each panel in the combiner box. others might do it differently. i have seen mc4 connector with a fuse built in.
as above post said, most would put a fuse or breaker on the input as well as the output on the controller. start from battery bank, back-trace/check the voltages, with patience you should be able to find where the gremlin is at.
Steven & Polly
2000 Country Coach Intrigue 40'
2014 Ford C-Max Energi