1) surge protector. Couple of options here, portable that plugs into the pedestal and trailer shore cord plugs into it or hard wired. In the hard wired version it is mounted inside the trailer between the breaker panel and the plug that the shore cord attaches to. You can get a "remote" monitor panel that you can mount on a wall that will display information. It is connected to the surge protector by a communication cable so a little pre planning would help if you went that route.
2) Battery cutoff. Not all units came with them from the factory. Most common place for factory switch is the front compartment, most often on the curb side. You can easily install one, just figure out where you want it. Then its just a matter of splicing it into the lead from the positive side of the battery(s) leading to the trailer, common color is black or red. Marinco makes a real nice one and I have installed many.
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2012 Copper Canyon 273FWRET being towed by a 1994 Ford F350 CC,LB,Dually diesel.
Airlift 5000 bags, Prodigy brake control, 5 gauges on the pillar.Used to tow a '97 Jayco 323RKS.
Now an RVIA registered tech. Retired from Law enforcement in 2008 after 25+ yrs.