The newer trailers are coming out with the AUTO RESET type circuit breaker coming off the battery. This fused purpose is to protect the wiring in case of short circuit down the line. It should be pretty hard to blow this fuse. Maybe you have added more batteries and need to increase this fuse value. Your batteries will demand around 20AMPS for each battery plus some safe zone. Usually a 30AMP FUSED circuit is for one 12VDC battery being charged...
I replaced my in-line fuse holder with BLUE SEA FUSE BLOCKS. I like the idea of having 4AWG RING TERMINALS everywhere for my battery connections.
Roy and Carolyn
I claim Horse Creek Country in Southern Ill - Momabear is from North Texas
We live in King George VA
RETIRED DOD DOAF DON CONTRACTOR Electronics Tech 42YRS
"We're burning daylight" - John Wayne
2008 STARCRAFT 14RT OFF-ROAD POPUP with PD9260C and three 85AH 12VDC batteries
2010 F150 FX4 5.4 GAS with 3.73 gears - Super Cab - Towing Package - 2KW Honda EU2000i Gen
K9PHT (since 1957) 146.52Mhz
"We always have a PLAN B"