Same thing happened to me with our jack. I found that if you go just a little too far past the hard stops of the tongue jack for just a split second, the extra tax on the motor causes the fuse to blow. Now I have a mark at the retracted position that I watch so I know when to let the switch go before hitting the hard stop.
The good news is that the first thing I did when I picked up the new trailer was go through the fuse panel and buy a pile of spares.
Originally Posted by arkhillbilly
I leave trailer/tv plugged in while unhooking. It provides extra power to t/t battery. If you raise or lower jack past certain levels, it will blow that 30a fuse. Place a four to six inch block under jack foot to use less of jack. Last things I unhook are safety chains, break away cable, then power chord. T/t's have been known to move while unhooking.