Hi Barry. Not sure of the layout of all the trailers but they should be on the very front outside of the trailer.
The easiest way is to follow the trailer portion of your wiring connector from the truck. The cable contains 7 wires and follows back along the tongue to a junction box where it connects to wires that operate the trailer lights, brakes etc. If you follow those wires to the front of the trailer there should be an access hole where they enter the underbelly. Along with the junction box wires at this point, you will find other wires going to the auto reset breakers usually located under a screw on plastic cowl, usually just off center on the front. If you take the cowl off you will find the breakers.
Not sure if they are all the same amperage but suspect they are. The wires connected here are for the slide, electric stabilizer, front electric jack and a jumper wire that runs back to the junction box to the trailer brake connection.
I have 3 reset breakers on mine. The positive cable from the battery is connected to one of the breaker studs (2 studs on each one) This breaker is connected to another breaker by a small metal plate giving both breakers 12v DC. The other studs contain the wires coming from the trailer for the slide, equalizer etc. An 8G wire from the trailer converter is also attached which charges the battery when on shore power. A jumper also goes to the 3rd breaker which runs the front tongue jack as well as a jumper wire back to the junction box for the brakes. This gives power to the brakes in the event the trailer breaks free of the truck while you are travelling down the road. Your break-away pin, which is attached to a cable clipped onto your truck bumper, will pull out of the box which will close the circuit sending a current to the brakes which will lock them up.
Hope I'm not confusing you on this. I spent lots of time trying to figure out this set up and have it in my head on how it should work but maybe can't explain it that well.
I have attached a picture of mine. DON'T BE CONFUSED BY WIRES THAT LOOK WHITE ATTACHED TO THE BREAKERS THEY ARE ACTUALLY BLACK. The white is the residue off a BLK/WHI cable. THERE SHOULD BE NO WHITE (GROUND) GOING TO THE BREAKERS
2014 Sunset Trail Reserve ST25RB
2013 Toyota Tundra Crewmax Platinum 5.7 Tow Package