If you had three in a row go bad on the same vehicle I'd suspect another issue.. Possibly a bad electrical connection "Up-Line" from the power unit.. or even a bad battery in the towed.
She does suck the amps when she brakes.
Another possible cause is the TC-6000 in the motor home, (And likewise the wires supporting it) it may be activating the power unit when it should not.
Another suspect is the control unit under the dash in the towed.. it too may be sending power to the power unit when it should not.
True story, much shortened.. A neighbor in one RV park came to me for help, strong wind and his power awning would not retract. I had to go to the method of last resort to roll it up for him and called Rachel the RV GIRL (That's her license plate).
She came out and diagnosed a bad motor, replaced it (Under warranty) then had to replace the replacement,, This time they also replaced the controller and the switch as the switch was sticking and the controller was not sensing the motor stall and cutting power as the Attwood (A&E Weatherpro) controllers are supposed to.
Your system may also have failure of either the master controller in the motor home or of the slave in the towed sending power to the solenoid and burning it out.
Home is where I park it!