Best way to check trlr brakes AND integr brake controller

Thanks for the education...assumptions are a dangerous thing sometimes...

Will have to really take note the next time one is apart

Now wonder how they manage to keep the self adjuster from over tightening when
it works in the forward direction

In reverse on 'cars' & 'trucks', there is a cable/rod/etc that has a spring on
the pawl to keep it from over tightening. Must be one there too...another assumption... :)